Device and method for performing communication via a plurality of component carriers

ABSTRACT

A device enabling a frequency band shared between wireless communication of a cellular system and other wireless communication to be more appropriately used in the cellular system. The device includes a control unit configured to occupy a frequency band shared between wireless communication of a cellular system and other wireless communication for the wireless communication of the cellular system during a first period and release the frequency band from the wireless communication of the cellular system during at least a second period corresponding to the first period.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims the benefit ofpriority under 35 U.S.C. § 120 from U.S. application Ser. No.15/124,320, filed Sep. 7, 2016, the entire contents of which is herebyincorporated herein by reference and which is a national stage ofInternational Application No. PCT/JP2014/083387, filed Dec. 17, 2014,which is based upon and claims the benefit of priority under 35 U.S.C. §119 to Japanese Patent Application No. 2014-052066, filed Mar. 14, 2014.

TECHNICAL FIELD

The present disclosure relates to a device and a method.

BACKGROUND ART

In the 3rd Generation Partnership Project (3GPP), various technologiesfor improving system throughput have been discussed. It may be said thata first shortcut for improving the system throughput is increasing afrequency to be used. In the 3GPP, the technology of carrier aggregation(CA) has been considered in Release 10 and Release 11. CA is atechnology for improving the system throughput and a maximum data rateby aggregating component carriers (CCs) having a bandwidth of 20 MHz foruse. A frequency band available as a CC must adopt the technology ofsuch CA. Thus, a frequency band available for wireless communication ofa cellular system is required.

For example, in Patent Literature 1, technology which enables aregistered frequency band available for a registered provider and anunlicensed band available when a predetermined condition is satisfied tobe used in addition to a dedicated frequency band allocated to eachprovider for exclusive use is disclosed.

CITATION LIST Patent Literature

Patent Literature 1: JP 2006-094001A

SUMMARY OF INVENTION Technical Problem

However, for example, when a frequency band to be used in other wirelesscommunication (for example, wireless communication of a wireless localarea network (LAN)) is also used in wireless communication of a cellularsystem, a variety of undesired results can be caused. That is, when afrequency band is shared between wireless communication of the cellularsystem and other wireless communication, a variety of undesired resultscan be caused.

As an example, the number of opportunities to use the above-mentionedfrequency band in the above-mentioned other wireless communication issignificantly reduced when the above-mentioned frequency band isexcessively used in the wireless communication of the above-mentionedcellular system. Thus, the sharing of the above-mentioned frequency bandcan be a disadvantage for the above-mentioned other wirelesscommunication.

As another example, a device of the above-mentioned cellular system canor cannot secure the above-mentioned frequency band for wirelesscommunication of the above-mentioned cellular system. Thus, starting touse the above-mentioned frequency band in wireless communication of theabove-mentioned cellular system can be time-consuming.

As still another example, there is a possibility of interferenceoccurring between wireless communication of the above-mentioned cellularsystem and the above-mentioned other wireless communication in theabove-mentioned frequency band when the above-mentioned frequency bandis used in the above-mentioned cellular system. Thus, communicationquality of the wireless communication of the above-mentioned cellularsystem and/or the above-mentioned other wireless communication candeteriorate.

Therefore, it is desirable to provide a mechanism which enables afrequency band shared between wireless communication of a cellularsystem and other wireless communication to be more appropriately used inthe cellular system.

Solution to Problem

According to the present disclosure, there is provided a deviceincluding: a control unit configured to occupy a frequency band sharedbetween wireless communication of a cellular system and other wirelesscommunication for the wireless communication of the cellular systemduring a first period and release the frequency band from the wirelesscommunication of the cellular system during at least a second periodcorresponding to the first period.

According to the present disclosure, there is provided a methodincluding: occupying, by a processor, a frequency band shared betweenwireless communication of a cellular system and other wirelesscommunication for the wireless communication of the cellular systemduring a first period and releasing the frequency band from the wirelesscommunication of the cellular system during at least a second periodcorresponding to the first period.

Advantageous Effects of Invention

According to the above-described present disclosure, a frequency bandshared between wireless communication of a cellular system and otherwireless communication can be more appropriately used in the cellularsystem. Note that the effects described above are not necessarilylimited, and along with or instead of the effects, any effect that isdesired to be introduced in the present specification or other effectsthat can be expected from the present specification may be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram illustrating a frame format ofInstitute of Electrical and Electronics Engineers (IEEE) 802.11.

FIG. 2 is an explanatory diagram illustrating a frame format oflong-term evolution (LTE).

FIG. 3 is an explanatory diagram illustrating an example of a schematicconfiguration of a cellular system according to an embodiment of thepresent disclosure.

FIG. 4 is an explanatory diagram illustrating an example of acommunication area of a wireless local area network (LAN) overlapping asmall cell.

FIG. 5 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a macro cell.

FIG. 6 is a block diagram illustrating an example of a configuration ofa base station according to a first embodiment.

FIG. 7 is an explanatory diagram illustrating a first example of periodsof occupancy and release of a shared band.

FIG. 8 is an explanatory diagram illustrating a second example ofperiods of occupancy and release of a shared band.

FIG. 9 is an explanatory diagram illustrating a third example of periodsof occupancy and release of a shared band.

FIG. 10 is an explanatory diagram illustrating a fourth example ofperiods of occupancy and release of a shared band.

FIG. 11 is a block diagram illustrating an example of a configuration ofa terminal device according to the first embodiment.

FIG. 12 is a flowchart illustrating a first example of a schematic flowof a process according to the first embodiment.

FIG. 13 is a flowchart illustrating a second example of a schematic flowof a process according to the first embodiment.

FIG. 14 is a flowchart illustrating a third example of a schematic flowof a process according to the first embodiment.

FIG. 15 is a flowchart illustrating a fourth example of a schematic flowof a process according to the first embodiment.

FIG. 16 is a block diagram illustrating an example of a configuration ofa base station according to a second embodiment.

FIG. 17 is an explanatory diagram illustrating transmission timings ofsignals.

FIG. 18 is an explanatory diagram illustrating an example oftransmission of a dummy signal.

FIG. 19 is a block diagram illustrating an example of a configuration ofa terminal device according to the second embodiment.

FIG. 20 is a flowchart illustrating a first example of a schematic flowof a process according to the second embodiment.

FIG. 21 is a flowchart illustrating a second example of a schematic flowof a process according to the second embodiment.

FIG. 22 is a block diagram illustrating an example of a configuration ofa base station according to a third embodiment.

FIG. 23 is an explanatory diagram illustrating an example of someresource blocks (RBs) in which a dummy signal is transmitted.

FIG. 24 is an explanatory diagram illustrating an example of a resourceelement (RE) in which a dummy signal is transmitted among some RBs.

FIG. 25 is an explanatory diagram illustrating an example of some REs inwhich a dummy signal is transmitted in each RB.

FIG. 26 is an explanatory diagram illustrating a first example of radioresources in which dummy signals are transmitted by a plurality ofterminal devices.

FIG. 27 is an explanatory diagram illustrating a second example of radioresources in which dummy signals are transmitted by a plurality ofterminal devices.

FIG. 28 is a block diagram illustrating an example of a configuration ofa terminal device according to the third embodiment.

FIG. 29 is a flowchart illustrating an example of a schematic flow of aprocess by a base station according to the third embodiment.

FIG. 30 is a flowchart illustrating an example of a schematic flow of aprocess by the terminal device according to the third embodiment.

FIG. 31 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 32 is a block diagram illustrating a second example of a schematicconfiguration of an eNB.

FIG. 33 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 34 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

DESCRIPTION OF EMBODIMENT(S)

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail and with reference to the attached drawings. Notethat, in this specification and the appended drawings, structuralelements that have substantially the same function and structure aredenoted with the same reference numerals, and repeated explanation ofthese structural elements is omitted.

Also, the description will be given in the following order.

1. Introduction

2. Schematic configuration of system

3. First embodiment

3.1. Summary

3.2. Configuration of base station

3.3. Configuration of terminal device

3.4. Flow of process

3.5. Modified example

4. Second embodiment

4.1. Summary

4.2. Configuration of base station

4.3. Configuration of terminal device

4.4. Flow of process

4.5. First modified example

4.6. Second modified example

4.7. Combination of second embodiment and first embodiment

5. Third embodiment

5.1. Summary

5.2. Configuration of base station

5.3. Configuration of terminal device

5.4. Flow of process

5.5. Modified example

5.6. Combination of third embodiment and first embodiment/secondembodiment

6. Application example

6.1. Application example related to base station

6.2. Application example related to terminal device

7. Conclusion

1. INTRODUCTION

First, sharing of a frequency band, technology of wireless communicationconforming to a wireless local area network (LAN) standard, andtechnology of wireless communication of a cellular system will bedescribed with reference to FIGS. 1 and 2.

(Sharing of Frequency Band)

A frequency band available for the wireless communication of thecellular system is required. For example, a band of 5 GHz is consideredas a frequency band for use in wireless communication of the cellularsystem (hereinafter referred to as “cellular communication”).

However, the band of 5 GHz is used in wireless communication conformingto the wireless LAN standard (hereinafter referred to as “wireless LANcommunication”). Thus, when the cellular system uses the band of 5 GHz,for example, the band of 5 GHz is shared between cellular communicationand wireless LAN communication. Specifically, for example, a frequencyband of 5 GHz (for example, a channel of a wireless LAN) is used in thewireless LAN communication at a certain time and used in the cellularcommunication at another time. Thereby, frequency utilization efficiencyof the band of 5 GHz is improved. Also, the wireless LAN standardincludes Institute of Electrical and Electronics Engineers (IEEE)802.11a, 11b, 11g, 11n, 11ac, and 11ad, etc. and these standards arecharacterized in that IEEE 802.11 is adopted for a media access control(MAC) layer.

Devices for performing wireless LAN communication are already widespreadin the world. Thus, from the viewpoint of backward compatibility, amechanism for sharing a frequency band between cellular communicationand wireless LAN communication without changing an operation of thedevice for performing the wireless LAN communication is considered asthe technology of Long Term Evolution (LTE) and is desired to be definedas a new standard of LTE. Also, a terminal device conforming to theabove-mentioned new standard uses the shared frequency band, but aterminal device which does not conform to the above-mentioned newstandard is considered as a terminal device not using the sharedfrequency band.

In LTE, LTE-Advanced, or a cellular system conforming to a communicationstandard equivalent thereto, the shared frequency band will be used as,for example, a component carrier (CC). Further, it is assumed that thefrequency band of the cellular system is used as a primary componentcarrier (PCC) and the shared frequency band is used as a secondarycomponent carrier (SCC). Also, a control signal and a data signal can betransmitted and received using a frequency band of the cellular systemand the data signal can be transmitted and received using the sharedfrequency band.

(Technology of Wireless Communication Conforming to Wireless LANStandard)

A frame format of IEEE 802.11 will be described as the technology ofwireless communication conforming to the wireless LAN standard withreference to FIG. 1. FIG. 1 is an explanatory diagram illustrating aframe format of IEEE 802.11.

In IEEE 802.11, a DATA frame and an acknowledgement (ACK) frame arebasic frames. When the DATA frame is correctly received, the ACK frameis a frame which causes a transmitting side to know the success ofreception of the DATA frame. Although wireless LAN communication can beperformed only by the DATA frame and the ACK frame, two frames such as arequest to send (RTS) frame and a clear to send (CTS) frame aregenerally further used.

Before the RTS frame is transmitted, each terminal device which performsthe wireless LAN communication confirms that no signal is transmittedduring a period referred to as a distributed coordination function (DCF)inter-frame space (DIFS). This is referred to as carrier sense. Whenterminal devices simultaneously start to transmit signals at a point intime at which the DIFS has elapsed, the signals may collide with eachother. Thus, each terminal device waits for a backoff time randomly setfor each terminal device and transmits a signal if no signal istransmitted for the backoff time.

Basically, the terminal device cannot transmit the signal while anysignal is detected. However, because there is a hidden terminal problem,an RTS frame and a CTS frame including a duration field for setting avalue referred to as a network allocation vector (NAV) are added. TheNAV is set on the basis of a value included in the duration field. Theterminal device setting the NAV avoids transmitting a signal during aperiod of the NAV.

First, a first terminal device for transmitting the DATA frame transmitsthe RTS frame. Then, another terminal device located around the firstterminal device receives the RTS frame and acquires a value included inthe duration field in the RTS frame. The other terminal device sets, forexample, its own NAV to the above-mentioned acquired value and avoidstransmitting a signal during the period of the NAV. For example, theperiod of the NAV is a period from the end of the RTS frame to the endof the ACK frame.

Also, a second terminal device for receiving the DATA frame transmitsthe CTS frame after only a short inter-frame space (SIFS) from the endof the RTS frame according to the reception of the RTS frame. Then,another terminal device located around the above-mentioned secondterminal device receives the CTS frame and acquires a value included inthe duration field in the CTS frame. The other terminal device sets, forexample, its own NAV to the above-mentioned acquired value and avoidstransmitting a signal during the period of the NAV. The period of theNAV is a period from the end of the CTS frame to the end of the ACKframe. Thereby, for example, it is possible to prevent the otherterminal device (that is, a hidden terminal for the above-mentionedfirst terminal device) close to the above-mentioned second terminaldevice without being close to the above-mentioned first terminal devicefrom transmitting a signal during communication of the above-mentionedfirst terminal device and the above-mentioned second terminal device.

Also, the RTS frame includes a frame control field, a reception addressfield, a transmission address field, and a frame check sequence (FCS) inaddition to the duration field. Also, the CTS frame includes a framecontrol field, a reception address field, and an FCS in addition to theduration field.

Also, the DIFS and the SIFS in the standard of the IEEE 802.11 serieshave, for example, the following lengths.

TABLE 1 802.11b 802.11g 802.11a 802.11n 802.11ac SIFS 10 us 10 us 16 us16 us 16 us DIFS 50 us 28 us 34 us 34 us 34 us

(Technology of Wireless Communication of Cellular System)

(a) Frame Format

The frame format of LTE will be described with reference to FIG. 2. FIG.2 is an explanatory diagram illustrating the frame format of LTE.

First, a unit of time such as a radio frame is used in LTE. One radioframe is 10 ms. Each radio frame is identified by a system frame number(SFN) which is any one of 0 to 1023.

The radio frame includes 10 sub-frames identified by #0 to #9. Eachsub-frame is 1 ms. Further, each sub-frame includes two slots and eachslot includes, for example, seven orthogonal frequency divisionmultiplexing (OFDM) symbols. That is, each sub-frame includes 14 OFDMsymbols. Also, the frame format illustrated in FIG. 2 is a frame formatof a downlink and the frame format of an uplink includes a singlecarrier frequency division multiple access (SC-FDMA) symbol in place ofan OFDM symbol.

(b) Carrier Aggregation

Component Carriers

With carrier aggregation in Release 10, up to a maximum of five CCs areaggregated for use by user equipment (UE). Each CC is a band with amaximum width of 20 MHz. Carrier aggregation includes a case in whichsuccessive CCs in the frequency direction are used, and a case in whichseparated CCs in the frequency direction are used. With carrieraggregation, the CCs to be used may be set for each UE.

PCC and SCC

In carrier aggregation, one of the multiple CCs used by a UE is aspecial CC. This special CC is called the primary component carrier(PCC). Also, the remaining CCs among the multiple CCs are calledsecondary component carriers (SCCs). The PCC may be different dependingon the UE.

Since the PCC is the most important CC among the multiple CCs, it isdesirable for the PCC to be the CC with the most stable communicationquality. Note that in actual practice, which CC to treat as the PCCdepends on the implementation.

The SCC is added to the PCC. In addition, an existing SCC that has beenadded may also be removed. Note that changing an SCC is conducted byremoving an existing SCC and adding a new SCC.

PCC Determination Method and Changing Method

When a UE connection is initially established and the status of the UEgoes from Radio Resource Control (RRC) Idle to RRC Connected, the CCthat the UE used during the establishment of the connection becomes thePCC for that UE. More specifically, a connection is established througha connection establishment procedure. At this point, the status of theUE goes from RRC Idle to RRC Connected. Also, the CC used in theprocedure becomes the PCC for the above UE. Note that the aboveprocedure is a procedure initiated from the UE side.

Additionally, PCC changing is conducted by a handover betweenfrequencies. More specifically, if a handover is specified in aconnection reconfiguration procedure, a PCC handover is conducted, andthe PCC is changed. Note that the above procedure is a procedureinitiated from the network side.

Adding SCC

As discussed above, the SCC is added to the PCC. As a result, the SCC isassociated with the PCC. In other words, the SCC is subordinate to thePCC. SSC addition may be conducted through a connection reconfigurationprocedure. Note that this procedure is a procedure initiated from thenetwork side.

Removing SSC

As discussed above, an SCC may be removed. SSC removal may be conductedthrough a connection reconfiguration procedure. Specifically, a specificSCC specified in a message is removed. Note that the above procedure isa procedure initiated from the network side.

In addition, the removal of all SCCs may be conducted through aconnection re-establishment procedure.

Special Role of PCC

The connection establishment procedure, the transmitting and receivingof non-access stratum (NAS) signaling, and the transmitting andreceiving of uplink control signals on the physical uplink controlchannel (PUCCH) are conducted only by the PCC, and not by the SCCs.

In addition, the detection of a radio link failure (RLF) and asubsequent connection re-establishment procedure are also conducted onlyby the PCC, and not by the SCCs.

(Conditions of Backhauling for Carrier Aggregation)

For example, an ACK of a downlink signal on an SCC is transmitted by thePUCCH of the PCC. Since the ACK is used for the retransmission of databy the evolved Node B (eNB), a delay of the ACK is not acceptable.Consequently, when a first eNB using a CC that acts as the PCC for a UEis different from a second eNB using a CC that acts as an SCC for theUE, a backhaul delay of approximately 10 ms between the first eNB andthe second eNB is desirable.

2. SCHEMATIC CONFIGURATION OF CELLULAR SYSTEM

Next, a schematic configuration of a cellular system 1 according to anembodiment of the present disclosure will be described with reference toFIGS. 3 to 5. FIG. 3 is an explanatory diagram illustrating an exampleof the schematic configuration of the cellular system 1 according to theembodiment of the present disclosure. Referring to FIG. 3, the system 1includes a base station 100 and a terminal device 200. The cellularsystem 1 is, for example, LTE, LTE-Advanced, or a system conforming to acommunication standard equivalent thereto.

(Base Station 100)

The base station 100 performs wireless communication (cellularcommunication) of the cellular system 1. That is, the base station 100performs wireless communication with the terminal device 200. Forexample, the base station 100 performs wireless communication with theterminal device 200 located within a cell 10 which is a communicationarea of the base station 100. Specifically, for example, the basestation 100 transmits a downlink signal to the terminal device 200 andreceives an uplink signal from the terminal device 200.

As an example, the base station 100 is a small base station and the cell10 is a small cell. As another example, the base station 100 may be amacro base station and the cell 10 may be a macro cell.

(Terminal Device 200)

The terminal device 200 performs wireless communication (cellularcommunication) of the cellular system.

For example, the terminal device 200 performs wireless communicationwith the base station 100. For example, when the terminal device 200 islocated within the cell 10 of the base station 100, the terminal device200 performs wireless communication with the base station 100.Specifically, for example, the terminal device 200 receives the downlinksignal from the base station 100 and transmits the uplink signal to thebase station 100.

Also, the terminal device 200 can perform wireless communication withanother terminal device (for example, another terminal device 200 or thelike). For example, the terminal device 200 can perform device-to-device(D2D) communication. Also, the terminal device 200 can perform wirelesscommunication within a localized network (LN) formed by the terminaldevice.

Also, the terminal device 200 may perform other wireless communication.For example, the terminal device 200 may perform wireless communication(wireless LAN communication) conforming to the wireless LAN standard.

(Frequency Band to be Used)

In wireless communication (that is, cellular communication) of thecellular system 1, the frequency band of the cellular system 1 is used.The frequency band is, for example, a band allocated to a provider ofthe cellular system 1, and can be referred to as a licensed band.

In particular, in the embodiment of the present disclosure, a frequencyband to be used in other wireless communication is also used in thecellular communication. That is, a frequency band shared between thecellular communication and the above-mentioned other wirelesscommunication (hereinafter referred to as a “shared band”) is also usedin the cellular communication. The above-mentioned other wirelesscommunication is, for example, wireless communication conforming to awireless LAN standard (that is, wireless LAN communication). Also, theabove-mentioned shared band is, for example, a channel of a wirelessLAN. As an example, the above-mentioned shared band is a channel of 20MHz.

(Other Wireless Communication)

A communication area of the above-mentioned other wireless communicationmay be located within the cell 10. That is, the cell 10 can overlap acommunication area of the above-mentioned other wireless communication.

For example, the other wireless communication is wireless LANcommunication and a communication area of the wireless LAN can belocated within the cell 10. That is, the cell 10 can overlap thecommunication area of the wireless LAN. Hereinafter, in this regard, aspecific example will be described with reference to FIGS. 4 and 5.

FIG. 4 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a small cell. Referringto FIG. 4, the base station 100 which is a small base station and theterminal device 200 are illustrated. Further, an access point 30 of awireless LAN and a terminal device 50 for performing wireless LANcommunication are located around the base station 100 and the terminaldevice 200. A communication area 40 of the access point 30 overlaps thecell 10 which is a small cell.

FIG. 5 is an explanatory diagram illustrating an example of acommunication area of a wireless LAN overlapping a macro cell. Referringto FIG. 5, the base station 100 which is a macro base station and theterminal device 200 are illustrated. Further, the access point 30 of awireless LAN and the terminal device 50 for performing wireless LANcommunication are located around the base station 100 and the terminaldevice 200. The communication area 40 of the access point 30 overlapsthe cell 10 which is a macro cell.

Also, the wireless LAN communication can include wireless communicationconforming to a wireless LAN standard between terminal devices whichperform the wireless LAN communication in addition to wirelesscommunication between the wireless LAN access point and the terminaldevice (which perform wireless LAN communication). As an example, thewireless LAN communication can also include wireless communicationaccording to Wi-Fi Direct.

The cellular system 1 according to the embodiment of the presentdisclosure has been described above. Also, the cellular system 1 caninclude a plurality of base stations 100 as well as one base station100. Also, the cellular system 1 can include another device in additionto the base station 100 and the terminal device 200. For example, thecellular system 1 can include core network nodes (for example, amobility management entity (MME), a serving gateway (S-GW), and a packetdata network gateway (P-GW), etc.).

3. FIRST EMBODIMENT

Next, the first embodiment of the present disclosure will be describedwith reference to FIGS. 6 to 15.

3.1. SUMMARY

First, the summary of the first embodiment will be described.

Problems Related to First Embodiment

When a frequency band is shared between the wireless communication ofthe cellular system (that is, cellular communication) and the otherwireless communication (for example, wireless LAN communication), thenumber of opportunities to use the above-mentioned frequency band in theabove-mentioned other wireless communication is significantly reduced ifthe frequency band is excessively used in the cellular communication.This becomes a disadvantage for a device which performs theabove-mentioned other wireless communication. Thus, when theabove-mentioned frequency band is shared, it is desirable to secure anopportunity to use the above-mentioned frequency band in theabove-mentioned other wireless communication. For example, it isdesirable that an opportunity to use the above-mentioned frequency bandbe fairly given to the cellular system and the device for performingother wireless communication. For example, because radio resources arefairly used between devices on the basis of a carrier sense multipleaccess with collision avoidance (CSMA/CA) in the wireless LANcommunication, it is important to secure fairness when theabove-mentioned other wireless communication is wireless LANcommunication.

Also, wireless communication is performed using a relatively long radioframe of 10 ms as a unit in the cellular system. Also, in the cellularsystem, the terminal device can transmit and receive data using theabove-mentioned frequency band by achieving synchronization according toa synchronization signal transmitted in a radio frame in a frequencyband, acquiring system information, and performing a series ofconnection establishment procedures. In consideration of this regard, itis desirable to continuously use the frequency band shared between thecellular communication and the other wireless communication for acertain amount of time for the cellular communication.

Therefore, it is desirable to provide a mechanism which enables thefrequency band shared between the cellular communication and the otherwireless communication to be more appropriately used in the cellularsystem. More specifically, it is desirable to provide a mechanismcapable of securing an opportunity to use the frequency band sharedbetween the cellular communication and the other wireless communicationin the above-mentioned other wireless communication and continuouslyusing the frequency band for a certain amount of time for the cellularcommunication.

Characteristics of First Embodiment

According to the first embodiment, the frequency band shared between thecellular communication and the other wireless communication is occupiedfor the above-mentioned cellular communication during a first period andreleased from the above-mentioned cellular communication during at leasta second period corresponding to the above-mentioned first period.

Thereby, for example, it is possible to secure an opportunity to use thefrequency band shared between the cellular communication and the otherwireless communication in the above-mentioned other wirelesscommunication and continuously use the frequency band for a certainamount of time for the cellular communication.

3.2. CONFIGURATION OF BASE STATION

Next, an example of the configuration of a base station 100-1 accordingto the first embodiment will be described with reference to FIGS. 6 to10. FIG. 6 is a block diagram illustrating an example of theconfiguration of the base station 100-1 according to the firstembodiment. Referring to FIG. 6, the base station 100-1 is equipped withan antenna unit 110, a wireless communication unit 120, a networkcommunication unit 130, a storage unit 140, and a processing unit 150.

(Antenna Unit 110)

The antenna unit 110 emits a signal output by the wireless communicationunit 120 into space as a radio wave. Additionally, the antenna unit 110converts a radio wave from space into a signal, and outputs the signalto the wireless communication unit 120.

(Wireless Communication Unit 120)

The wireless communication unit 120 transmits and receives signals. Forexample, the wireless communication unit 120 transmits a downlink signalto a terminal device 200-1 positioned within the cell 10, and receivesan uplink signal from the terminal device 200-1 positioned within thecell 10.

For example, the wireless communication unit 120 transmits and receivesa signal using the frequency band of the cellular system 1. Also,particularly, in the embodiment of the present disclosure, the wirelesscommunication unit 120 transmits and receives a signal using thefrequency band shared between the cellular communication and the otherwireless communication (for example, wireless LAN communication) (thatis, a shared band).

(Network Communication Unit 130)

The network communication unit 130 communicates with other nodes. Forexample, the network communication unit 130 communicates with corenetwork nodes (for example, MME, S-GA, P-GW, etc.).Also, the networkcommunication unit 130 communicates with another base station 100-1.

(Storage Unit 140)

The storage unit 140 temporarily or permanently stores programs and datafor the operation of the base station 100-1.

(Processing Unit 150)

The processing unit 150 provides various functions of the base station100-1. The processing unit 150 includes a communication control unit151. Also, the processing unit 150 can further include another componentin addition to the communication control unit 151.

(Communication Control Unit 151)

The communication control unit 151 occupies the shared band (that is,the frequency band shared between the cellular communication and theother wireless communication) for the above-mentioned cellularcommunication during the first period, and releases the above-mentionedshared band from the above-mentioned cellular communication during thesecond period corresponding to the above-mentioned first period.

(a) Other Wireless Communication

For example, the above-mentioned other wireless communication iswireless communication conforming to the wireless LAN standard (that is,wireless LAN communication). In this case, the above-mentioned sharedband is shared between the cellular communication and the wireless LANcommunication. The above-mentioned shared band is, for example, achannel of a wireless LAN. As an example, the shared band is the channelof 20 MHz.

(b) Occupancy of Shared Band

Occupancy by Transmission of Signal for First Period

For example, the communication control unit 151 occupies theabove-mentioned shared band for the above-mentioned cellularcommunication during the above-mentioned first period by controlling thewireless communication device for performing wireless communication(cellular communication) of the cellular system 1 so that theabove-mentioned wireless communication device transmits a signal usingthe above-mentioned shared band during the above-mentioned first period.

For example, the above-mentioned wireless communication device is thebase station 100-1, and the communication control unit 151 controls thebase station 100-1 so that the base station 100-1 transmits a signalusing the above-mentioned shared band during the above-mentioned firstperiod. More specifically, for example, the communication control unit151 allocates a radio resource of the above-mentioned shared band to anysignal during the above-mentioned first period. Also, for example, thecommunication control unit 151 maps the signal to the radio resource ofthe above-mentioned shared band during the above-mentioned first period.

Also, the above-mentioned wireless communication device may be theterminal device 200-1 and the communication control unit 151 may controlthe terminal device 200-1 so that the terminal device 200-1 transmits asignal using the shared band during the above-mentioned first period.More specifically, for example, the communication control unit 151 mayinstruct the terminal device 200-1 to transmit the signal using theabove-mentioned shared band during the above-mentioned first period. Forexample, this instruction may be performed according to radio resourcecontrol (RRC) signaling or system information (SI).

For example, as described above, the wireless communication device (thatis, at least one of the base station 100-1 and the terminal device200-1) is controlled. Also, as a specific technique for transmitting asignal by the wireless communication device, for example, a techniquedescribed in a third embodiment can be applied. Also, as the signaltransmission technique, a technique described in a second embodiment canalso be applied.

As described above, for example, by transmitting the signal using theabove-mentioned shared band during the above-mentioned first period, adevice for performing the above-mentioned other wireless communication(for example, wireless LAN communication) detects the signal transmittedusing the above-mentioned shared band and avoids using the shared band.Thus, the above-mentioned shared band can be occupied for cellularcommunication.

Occupancy by Transmission of Frame for Setting NAV

The above-mentioned other wireless communication is wireless LANcommunication and the communication control unit 151 may occupy theabove-mentioned shared band for the above-mentioned cellularcommunication during the above-mentioned first period by controlling awireless communication device for performing the cellular communicationso that the above-mentioned wireless communication device transmits aframe including duration information for setting the NAV using theabove-mentioned shared band.

The above-mentioned wireless communication device may be at least one ofthe base station 100-1 and the terminal device 200-1.

Also, the above-mentioned frame may be the RTS frame, the CTS frame, ora frame similar thereto. The above-mentioned duration information may bea value included in the duration field. Also, the above-mentionedwireless communication device may transmit one frame including theduration information for setting the NAV to cover the whole of theabove-mentioned first period. Alternatively, the above-mentionedwireless communication device may transmit two or more frames atdifferent timings. Every time each of the above-mentioned two or moreframes is transmitted, the NAV of the device for receiving the frame maybe updated and the updated NAV may cover the whole of theabove-mentioned first period.

Through the transmission of the above-mentioned frame, for example, thedevice for performing the above-mentioned other wireless communication(for example, wireless LAN communication) sets the NAV and avoids theuse of the above-mentioned shared band. Thus, the above-mentioned sharedband can be occupied for the cellular communication.

(c) Release of Shared Band

For example, the communication control unit 151 releases theabove-mentioned shared band from the above-mentioned cellularcommunication during at least the above-mentioned second period bycontrolling a wireless communication device for performing wirelesscommunication (cellular communication) of the cellular system 1 so thatthe above-mentioned wireless communication device does not transmit asignal using the above-mentioned shared band during at least theabove-mentioned second period.

For example, the above-mentioned wireless communication device is thebase station 100-1, and the communication control unit 151 controls thebase station 100-1 so that the base station 100-1 does not transmit asignal using the above-mentioned shared band during at least theabove-mentioned second period. Also, for example, the above-mentionedwireless communication device may be the terminal device 200-1, and thecommunication control unit 151 controls the terminal device 200-1 sothat the terminal device 200-1 does not transmit a signal using theabove-mentioned shared band during the above-mentioned second period.More specifically, for example, the communication control unit 151 stopsthe use of the above-mentioned shared band during at least theabove-mentioned second period.

As described above, no signal is transmitted using the above-mentionedshared band during at least the above-mentioned second period, forexample, so that a device for performing the above-mentioned otherwireless communication (for example, wireless LAN communication) canperform the above-mentioned other wireless communication using theabove-mentioned shared band without being affected by the cellularcommunication. That is, the above-mentioned shared band can be releasedfrom the cellular communication.

(d) First Period and Second Period

Lengths of First Period and Second Period

The above-mentioned first period is a period of one or more radio framesof the cellular system 1. That is, the above-mentioned shared band isoccupied for cellular communication during the period of one or moreradio frames. Thereby, for example, the cellular communication can beenabled using the above-mentioned shared band. Also, the above-mentionedfirst period can be a period (for example, about 30 sec) which is longerthan one radio frame.

Also, for example, the above-mentioned second period has a lengthsimilar to that of the above-mentioned first period. That is, theabove-mentioned shared band is occupied for cellular communicationduring the first period and released from the cellular communicationduring at least a period having a length similar to that of the firstperiod. As an example, the above-mentioned second period has a lengthwhich is 90% to 110% of the length of the above-mentioned first period.Thereby, for example, fairness between the cellular communication andthe other wireless communication (for example, wireless LANcommunication) is secured.

Also, the above-mentioned second period may have a length which is apredetermined ratio of the length of the above-mentioned first period.As an example, the above-mentioned second period may have a length whichis 150% of the length of the above-mentioned first period. As anotherexample, the above-mentioned second period may have a length which is60% of the length of the above-mentioned first period.

Also, the lengths of the above-mentioned first period and theabove-mentioned second period may be fixed. Alternatively, the lengthsof the above-mentioned first period and the above-mentioned secondperiod may be variable, the length of the above-mentioned second periodmay change according to the length of the above-mentioned first period,or the length of the above-mentioned first period may change accordingto the length of the above-mentioned second period.

When First Period is Continuous Period

For example, the above-mentioned first period is a continuous period.That is, the above-mentioned shared band is occupied for cellularcommunication during the continuous first period.

Thereby, for example, it is possible to efficiently use theabove-mentioned shared band for the cellular communication. Morespecifically, for example, operations such as synchronizationachievement, acquisition of system information, and a series ofconnection establishment procedures are necessary in the terminal deviceto start the use of the above-mentioned shared band. Thus, when theabove-mentioned shared band is used for the continuous time, a frequencyof the above-mentioned operation is further reduced, and the terminaldevice 200-1 can efficiently use the above-mentioned shared band.

Also, for example, the above-mentioned second period is a periodimmediately before or immediately after the above-mentioned firstperiod. Thereby, for example, it is possible to reliably secure anopportunity to use the above-mentioned shared band in the other wirelesscommunication before and after the use of the above-mentioned sharedband in the cellular system 1.

FIRST EXAMPLE

As the first example, the above-mentioned second period is a continuousperiod immediately after the above-mentioned first period. Hereinafter,in this regard, a specific example will be described with reference toFIG. 7.

FIG. 7 is an explanatory diagram illustrating a first example of periodsof occupancy and release of a shared band. For example, a first period61 is a continuous period and a second period 63 is a continuous periodimmediately after the first period 61. That is, the shared band isoccupied for the cellular communication during the continuous firstperiod 61 and then released from the cellular communication during atleast the continuous second period.

Thereby, for example, the cellular system 1 can more quickly start theuse of the above-mentioned shared band as necessary. Also, the number ofopportunities to use the above-mentioned shared band in theabove-mentioned other wireless communication can further increase.

SECOND EXAMPLE

As the second example, the above-mentioned second period may be a periodimmediately before the above-mentioned first period and a periodimmediately after the above-mentioned first period. Hereinafter, in thisregard, a specific example will be described with reference to FIG. 8.

FIG. 8 is an explanatory diagram illustrating the second example of theoccupancy of the shared band and the period of the release. For example,the first period 61 is a continuous period and the second period 63 is aperiod immediately before the first period 61 and a period immediatelyafter the first period 61. That is, the shared band is occupied for thecellular communication during the continuous first period 61 after beingreleased from the cellular communication during a partial period of thesecond period 63 and then released from the cellular communicationduring the remaining period of the second period 63.

Thereby, for example, the cellular system 1 can quickly start the use ofthe above-mentioned shared band as necessary. Also, a time period inwhich the above-mentioned frequency band is used for cellularcommunication can further increase.

THIRD EXAMPLE

As the third example, the above-mentioned second period may be acontinuous period immediately before the above-mentioned first period.Hereinafter, in this regard, a specific example will be described withreference to FIG. 9.

FIG. 9 is an explanatory diagram illustrating the third example of theoccupancy and release of the shared band. For example, the first period61 is a continuous period and the second period 63 is a periodimmediately before the first period 61. That is, the shared band isreleased from the cellular communication during at least the continuoussecond period and then occupied for the cellular communication duringthe continuous first period 61.

Thereby, for example, on condition that an opportunity to use the sharedband in the above-mentioned wireless communication is secured, theabove-mentioned shared band is available for cellular communication.Thus, it is possible to more reliably secure an opportunity to use theabove-mentioned shared band in the other wireless communication.

When First Period is Discontinuous Period

The above-mentioned first period may be a discontinuous period. Thecommunication control unit 151 may occupy the shared band for thecellular communication during the above-mentioned first period andrelease the above-mentioned shared band from the above-mentionedcellular communication during at least the above-mentioned secondperiod, within a third period. Hereinafter, in this regard, a specificexample will be described with reference to FIG. 10.

FIG. 10 is an explanatory diagram illustrating a fourth example of theoccupancy and release of the shared band. For example, the first period61 is a discontinuous period and the second period 63 is also adiscontinuous period. In a third period 65, the shared band is occupiedfor the cellular communication during the discontinuous first period 61and the shared band is released from the cellular communication duringthe second period 63. As an example, the third period 65 is a periodhaving a fixed length and an upper-limit time in which the shared bandavailable for the cellular communication is defined within the thirdperiod 65. When an occupancy period (that is, the first period 61) ofthe shared band reaches the above-mentioned upper-limit period, theshared band is released from the cellular communication until the thirdperiod 65 has elapsed.

Thereby, it is possible to reliably secure an opportunity to use theabove-mentioned shared band in the above-mentioned other wirelesscommunication.

As described above, the communication control unit 151 occupies theabove-mentioned shared band for the cellular communication during theabove-mentioned first period and releases the above-mentioned sharedband from the cellular communication during at least the above-mentionedsecond period. Thereby, it is possible to secure an opportunity to use afrequency band shared between the cellular communication and the otherwireless communication (that is, a shared band) in the above-mentionedother wireless communication and continuously use the frequency band forthe cellular communication for a certain amount of time.

3.3. CONFIGURATION OF TERMINAL DEVICE

Next, an example of a configuration of the terminal device 200-1according to the first embodiment will be described with reference toFIG. 11. FIG. 11 is a block diagram illustrating the example of theconfiguration of the terminal device 200-1 according to the firstembodiment. Referring to FIG. 11, the terminal device 200-1 includes anantenna unit 210, a wireless communication unit 220, a storage unit 230,and a processing unit 240.

(Antenna Unit 210)

The antenna unit 210 emits a signal output by the wireless communicationunit 220 into space as a radio wave. Additionally, the antenna unit 210converts a radio wave from space into a signal, and outputs the signalto the wireless communication unit 220.

(Wireless Communication Unit 220)

The wireless communication unit 220 transmits and receives a signal. Forexample, the wireless communication unit 220 receives a downlink signalfrom the base station 100-1 and transmits an uplink signal to the basestation 100-1 when the terminal device 200-1 is located within the cell10.

For example, the wireless communication unit 220 transmits and receivesa signal using a frequency band of the cellular system 1. Also,particularly, in the embodiment of the present disclosure, the wirelesscommunication unit 220 transmits and receives a signal using a frequencyband shared between cellular communication and other wirelesscommunication (for example, wireless LAN communication) (that is, ashared band).

(Storage Unit 230)

The storage unit 230 temporarily or permanently stores programs and datafor the operation of the terminal device 200-1.

(Processing Unit 240)

The processing unit 240 provides various functions of the terminaldevice 200-1. The processing unit 240 includes a communication controlunit 241. Also, the processing unit 240 can further include othercomponents in addition to the communication control unit 241.

(Communication Control Unit 241)

The communication control unit 241 controls the terminal device 200-1.

Particularly, in the first embodiment, the communication control unit241 may control the terminal device 200 so that the terminal device200-1 transmits a signal using the above-mentioned shared band duringthe above-mentioned first period. For example, the communication controlunit 241 may control the terminal device 200 so that the terminal device200-1 transmits a signal using the above-mentioned shared band duringthe above-mentioned first period according to an instruction of the basestation 100-1.

Also, as a specific technique of transmitting a signal, a techniquedescribed in the third embodiment may be applied. Also, as the techniqueof transmitting the signal, the technique described in the secondembodiment may also be applied.

3.4. FLOW OF PROCESS

Next, an example of a process according to the first embodiment will bedescribed with reference to FIGS. 12 to 15.

FIRST EXAMPLE

FIG. 12 is a flowchart illustrating the first example of a schematicflow of the process according to the first embodiment. The process is anexample of when the occupancy and release of the shared band asillustrated in FIG. 7 are performed.

The communication control unit 151 determines whether to use the sharedband (that is, a frequency band shared between cellular communicationand other wireless communication) (S301). When it is determined not touse the above-mentioned shared band (S301: NO), the process returns tostep S301.

On the other hand, when it is determined to use the above-mentionedshared band (S301: YES), the communication control unit 151 occupies theabove-mentioned shared band for the cellular communication during thefirst period (S303). In the first period, the cellular communication isperformed.

Thereafter, the communication control unit 151 releases theabove-mentioned shared band from the cellular communication during thesecond period (S305). The process returns to step S301.

SECOND EXAMPLE

FIG. 13 is a flowchart illustrating the second example of a schematicflow of the process according to the first embodiment. The process is anexample of when the occupancy and release of the shared band asillustrated in FIG. 8 are performed.

The communication control unit 151 determines whether to use the sharedband (that is, a frequency band shared between cellular communicationand other wireless communication) (S311).

When it is determined not to use the above-mentioned shared band (S311:NO), the communication control unit 151 calculates an additional releasetime for the above-mentioned shared band (S313). The process returns tostep S311. Also, the above-mentioned additional release time is a periodin which the above-mentioned shared band is released further after therelease of the second period.

On the other hand, when it is determined to use the above-mentionedshared band (S311: YES), the communication control unit 151 occupies theabove-mentioned shared band for the cellular communication during thefirst period (S315). In the first period, the cellular communication isperformed.

Thereafter, the communication control unit 151 releases theabove-mentioned shared band from the cellular communication during theremaining period of the second period (that is, a period of a differencebetween the second period and the additional release period) (S317). Theprocess returns to step S311.

THIRD EXAMPLE

FIG. 14 is a flowchart illustrating the third example of a schematicflow of the process according to the first embodiment. The process is anexample of when the occupancy and release of the shared band asillustrated in FIG. 9 are performed.

The communication control unit 151 determines whether to use the sharedband (that is, a frequency band shared between cellular communicationand other wireless communication) (S321).

When it is determined to use the above-mentioned shared band (S321:YES), the communication control unit 151 determines whether theabove-mentioned shared band has already been released during the secondperiod (S323).

When it is determined that the above-mentioned shared band has alreadybeen released during the second period (S323: YES), the communicationcontrol unit 151 occupies the above-mentioned shared band for thecellular communication during the first period (S325). In the firstperiod, the cellular communication is performed. Thereafter, the processreturns to step S321.

On the other hand, when it is determined not to use the above-mentionedshared band (S321: NO) and when it is determined that theabove-mentioned shared band has not yet been released during the secondperiod (S323: NO), the communication control unit 151 calculates arelease time for the above-mentioned shared band (S327). The processreturns to step S321.

FOURTH EXAMPLE

FIG. 15 is a flowchart illustrating the fourth example of a schematicflow of the process according to the first embodiment. The process is anexample of when the occupancy and release of the shared band asillustrated in FIG. 10 are performed. The above-mentioned process isperformed during the third period.

The communication control unit 151 determines whether to use the sharedband (that is, a frequency band shared between cellular communicationand other wireless communication) (S331).

When it is determined to use the above-mentioned shared band (S331:YES), the communication control unit 151 occupies the above-mentionedshared band for the cellular communication (S333). In the first period,the cellular communication is performed. Thereafter, the communicationcontrol unit 151 determines whether an occupancy period (the firstperiod) of the above-mentioned shared band has reached an upper limit(S335).

When it is determined not to use the above-mentioned shared band (S331:YES) and it is determined that the above-mentioned shared period (thefirst period) has not reached the upper limit (S335: YES), thecommunication control unit 151 releases the above-mentioned shared bandfrom the cellular communication (S337). The process returns to stepS331.

On the other hand, when it is determined that the above-mentionedoccupancy period (the first period) has reached the upper limit (S335:YES), the communication control unit 151 releases the above-mentionedshared band from the cellular communication during the remaining periodof the third period (S339). The process ends.

3.5. MODIFIED EXAMPLE

(Summary)

In the above-mentioned example of the first embodiment, for example, thebase station 100-1 (the communication control unit 151) occupies theshared band for the cellular communication during the first period andreleases the above-mentioned shared band from the above-mentionedcellular communication during at least the second period correspondingto the above-mentioned first period.

On the other hand, in a modified example of the first embodiment, theterminal device 200-1 (the communication control unit 241) occupies theshared band for the cellular communication during the first period andreleases the above-mentioned shared band from the cellular communicationduring at least the second period corresponding to the above-mentionedfirst period.

Thereby, for example, it is possible to secure an opportunity to use afrequency band shared between cellular communication and other wirelesscommunication (that is, a shared band) in the above-mentioned othercommunication and continuously use the frequency band for wirelesscommunication between terminal devices in the cellular system 1 (forexample, D2D communication or wireless communication within the LN) fora certain amount of time.

Also, even in the above-mentioned modified example of the firstembodiment, for example, the base station 100-1 (the communicationcontrol unit 151) may occupy the shared band for the cellularcommunication during the first period and release the above-mentionedshared band from the above-mentioned cellular communication during atleast the second period corresponding to the above-mentioned firstperiod.

(Terminal Device 200-1: Communication Control Unit 241)

In the modified example of the first embodiment, the communicationcontrol unit 271 occupies the shared band (that is, a frequency bandshared between cellular communication and other wireless communication)during the first period and releases the above-descried shared band fromthe above-mentioned cellular communication during at least the secondperiod corresponding to the above-mentioned first period.

The description of the communication control unit 241 in this regard isthe same as the corresponding description for the communication controlunit 151 according to the above-mentioned first embodiment except fordifferences related to the main components (the base station 100-1 andthe terminal device 200-1). Consequently, here, redundant descriptionwill be omitted.

(Flow of Process)

An example of a process of the terminal device 200-1 according to themodified example of the first embodiment is the same as the example ofthe process of the base station 100-1 described with reference to FIGS.12 to 15 except for the differences related to the main components (thebase station 100-1 and the terminal device 200-1). Consequently, here,redundant description will be omitted.

4. SECOND EMBODIMENT

Next, the second embodiment of the present disclosure will be describedwith reference to FIGS. 16 to 21.

4.1. SUMMARY

First, the summary of the second embodiment will be described.

Problems According to Second Embodiment

In the wireless LAN standard, CSMA/CA is adopted. For example, the casein which a device (the base station 100 or the terminal device 200) ofthe cellular system 1 also operates on the basis of the CSMA/CA isconsidered to use the frequency band used in the wireless LANcommunication in cellular communication. However, in this case, ofcourse, the device for performing wireless LAN communication can firstuse the above-mentioned frequency band and the above-mentioned device ofthe cellular system 1 may be unlikely to use the above-mentionedfrequency band. That is, the above-mentioned device of the cellularsystem 1 can or cannot secure the above-mentioned frequency band for thecellular communication. Thus, starting to use the above-mentionedfrequency band in wireless communication of the above-mentioned cellularsystem can be time-consuming.

Therefore, it is desirable to provide a mechanism for enabling thefrequency band shared between cellular communication and other wirelesscommunication to be more appropriately used in the cellular system. Morespecifically, it is desirable to provide a mechanism capable of morereliably securing the above-mentioned shared band for the cellularcommunication

Characteristics of Second Embodiment

According to the second embodiment, for example, a wirelesscommunication device for performing the cellular communication iscontrolled so that the above-mentioned wireless communication devicestarts to transmit a signal using a frequency band shared between thecellular communication and the wireless LAN communication (that is, ashared band) before a period in which no signal is transmitted using theabove-mentioned frequency band becomes a DIFS. Thereby, it is possibleto more reliably secure the above-mentioned frequency band for thecellular communication.

Also, according to the second embodiment, a wireless communicationdevice for performing cellular communication is controlled so that theabove-mentioned wireless communication device transmits a dummy signalusing the frequency band shared between the cellular communication andthe wireless LAN communication (that is, the shared band), for example,during a period until a radio frame for another frequency band used forthe cellular communication starts. Thereby, for example, it is possibleto more reliably secure the above-mentioned frequency band for thecellular communication.

4.2. CONFIGURATION OF BASE STATION

Next, an example of the configuration of a base station 100-2 accordingto the second embodiment will be described with reference to FIGS. 16 to18. FIG. 16 is a block diagram illustrating an example of theconfiguration of the base station 100-2 according to the secondembodiment. Referring to FIG. 16, the base station 100-2 is equippedwith an antenna unit 110, a wireless communication unit 120, a networkcommunication unit 130, a storage unit 140, and a processing unit 160.

Here, the description of the antenna unit 110, the wirelesscommunication unit 120, the network communication unit 130, and thestorage unit 140 is not different between the first embodiment and thesecond embodiment except for a difference of reference signs.Consequently, here, only the processing unit 160 will be described andredundant description will be omitted.

(Processing Unit 160)

The processing unit 160 provides various functions of the base station100-2. The processing unit 160 includes a communication control unit161. Also, the processing unit 160 can further include other componentsin addition to the communication control unit 161.

(Communication Control Unit 161)

(a) First Control for Securing Shared Band

For example, the communication control unit 161 controls a wirelesscommunication device for performing the above-mentioned cellularcommunication so that the above-mentioned wireless communication devicestarts to transmit a signal using the above-mentioned shared band beforea period in which no signal is transmitted using the shared band becomesa DIFS. The above-mentioned shared band is a frequency band to be sharedbetween wireless communication of the cellular system 1 (that is, acellular communication) and wireless communication conforming to awireless LAN standard (that is, wireless LAN communication).

Further, for example, the communication control unit 161 controls theabove-mentioned wireless communication device so that theabove-mentioned wireless communication device starts to transmit asignal using the above-mentioned shared band after the period in whichno signal is transmitted using the shared band is longer than an SIFS.

For example, the above-mentioned wireless communication device is thebase station 100-2 and the communication control unit 161 controls thebase station 100-2 so that the base station 100-2 starts to transmit asignal using the above-mentioned shared band after the period in whichno signal is transmitted using the shared band is longer than the SIFSand before the period becomes the DIFS. More specifically, for example,the processing unit 160 (the communication control unit 161 or anothercomponent) determines whether the signal is transmitted using theabove-mentioned shared band on the basis of a result of receiving asignal by the wireless communication unit 120. Also, the processing unit160 (the communication control unit 161 or another component) measuresthe period in which no signal is transmitted using the shared band. Thecommunication control unit 161 causes the wireless communication unit120 to transmit the signal using the above-mentioned shared band afterthe period in which no signal is transmitted using the above-mentionedshared band is longer than the SIFS and before the period becomes theDIFS. As an example, when the above-mentioned period becomes apredetermined period longer than the SIFS and shorter than the DIFS, thesignal is transmitted using the above-mentioned shared band.Hereinafter, in this regard, a specific example will be described withreference to FIG. 17.

FIG. 17 is an explanatory diagram illustrating transmission timings ofsignals. Referring to FIG. 17, a signal starts to be transmitted beforethe period in which no signal is transmitted using the shared bandbecomes the DIFS and after the period is longer than the SIFS. As anexample, the signal starts to be transmitted when a predetermined periodlonger than the SIFS and shorter than the DIFS has elapsed.

When a period in which no signal is transmitted reaches a sum of theDIFS and a backoff time, a device for performing the wireless LANcommunication can transmit the signal. Thus, the signal starts to betransmitted before the passage of the above-mentioned DIFS so that it ispossible to transmit the signal, for example, before a transmission timeof the device for performing the wireless LAN communication. As aresult, the transmission of the signal using the above-mentioned sharedband by the device for performing the wireless LAN communication can besuppressed. As described above, it is possible to more reliably securethe above-mentioned shared band for the cellular communication.

Also, it is possible to prevent a signal to be transmitted fromcolliding with a signal of wireless LAN communication by starting totransmit a signal after the passage of the SIFS as described above. Morespecifically, for example, an RTS frame, a CTS frame, a DATA frame, andan ACK frame are connected at a time interval of the SIFS. Thus, whenthe signal is transmitted before the passage of the SIFS, the signal cancollide with a signal of any of the CTS frame, the DATA frame, or theACK frame. Therefore, as described above, the collision between thesignal and the signal of the CTS frame, the DATA frame, or the ACK framecan be avoided if the signal starts to be transmitted after the periodin which no signal is transmitted using the above-mentioned shared bandis longer than the SIFS.

(b) Second Control for Securing Shared Band

Transmission of a Signal Until a Start of a Frame for Another FrequencyBand

For example, the communication control unit 161 controls a wirelesscommunication device for performing the above-mentioned cellularcommunication so that the above-mentioned wireless communication devicetransmits a dummy signal using the shared band during a period until aradio frame for another frequency band used in cellular communicationstarts. The above-mentioned shared band is a frequency band to be usedbetween wireless communication of the cellular system 1 (that is,cellular communication) and wireless communication conforming to awireless LAN standard (that is, wireless LAN communication).

For example, the above-mentioned wireless communication device is thebase station 100-2. Also, for example, the above-mentioned shared bandis a CC for the cellular system 1 and the above-mentioned otherfrequency band is another CC for the cellular system 1. Thecommunication control unit 161 controls the base station 100-2 so thatthe base station 100-2 transmits a dummy signal using a shared band (theCC) during a period until a radio frame for the other CC starts. Morespecifically, for example, the communication control unit 161 causes thewireless communication unit 120 to transmit the dummy signal during aperiod until the radio frame for the other CC starts from a timingbefore the passage of the DIFS and after the passage of the SIFS.Hereinafter, in this regard, a specific example will be described withreference to FIG. 18.

FIG. 18 is an explanatory diagram illustrating an example oftransmission of a dummy signal. Referring to FIG. 18, the dummy signalstarts to be transmitted using the above-mentioned shared band after nosignal is transmitted using the shared band (the CC) (for example, afterthe period in which no signal is transmitted using the shared band islonger than the SIFS and before the period becomes the DIFS asillustrated in FIG. 17). The above-mentioned dummy signal is transmitteduntil the radio frame of the other CC (and a radio frame of theabove-mentioned shared band) starts. Thereafter, a signal of thecellular system is transmitted and received in the radio frame using theabove-mentioned CC and the above-mentioned shared band.

The dummy signal is transmitted during a period until the radio framefor the above-mentioned other frequency band starts using theabove-mentioned shared band so that the transmission of the signal usingthe above-mentioned shared band by the device for performing wirelessLAN communication can be suppressed until the start of theabove-mentioned radio frame. That is, the above-mentioned shared band issecured until the start of the above-mentioned radio frame. Thus, forexample, it is possible to start a radio frame for the above-mentionedshared band at the timing at which a radio frame for another frequencyband for cellular communication starts. As described above, it ispossible to more reliably secure the above-mentioned shared band forcellular communication while synchronizing a radio frame for the sharedband and a radio frame for the above-mentioned other frequency band.

Also, the above-mentioned dummy signal is, for example, any signal otherthan signals (a control signal and a data signal) of the cellularsystem. The above-mentioned dummy signal can become a busy tone for thedevice for performing the wireless LAN communication

Also, in other wthe period until the radio frame for the above-mentionedother frequency band starts is a period until a sub-frame of #0 for theabove-mentioned other frequency band starts.

Transmission of Radio Frame for Setting NAV

Also, in place of the transmission of the above-mentioned dummy signal,the communication control unit 161 may control the above-mentionedwireless communication device so that the above-mentioned wirelesscommunication device transmits a frame including duration informationfor setting the NAV using the above-mentioned shared band before theradio frame for the above-mentioned frequency band starts.

For example, the above-mentioned wireless communication device is thebase station 100-2. Also, the above-mentioned shared band may be a CCfor the cellular system 1 and the above-mentioned other frequency bandmay be another CC for the cellular system 1. Also, the above-mentionedframe may be an RTS frame, a CTS frame, or a frame similar thereto. Thecommunication control unit 161 may control the base station 100-2 sothat the base station 100-2 transmits the above-mentioned frame usingthe above-mentioned shared band before the radio frame for the other CCstarts. More specifically, for example, the communication control unit161 may generate the above-mentioned frame and cause the wirelesscommunication unit 120 to transmit the above-mentioned frame using theabove-mentioned shared band before the radio frame for the other CCstarts.

Also, the above-mentioned wireless communication device may transmit oneframe including duration information for setting the NAV to cover aperiod until a radio frame for the above-mentioned other frequency bandstarts. Alternatively, the above-mentioned wireless communication devicemay transmit two or more frames at different timings. Every time each ofthe above-mentioned two or more frames is transmitted, the NAV of thedevice for receiving the frame may be updated and the updated NAV maycover the whole of a period until the radio frame for theabove-mentioned other frequency band starts.

For example, the above-mentioned frame is transmitted, for example, sothat the device for performing the wireless LAN communication sets theNAV and avoids using the above-mentioned shared band. Thus, until thestart of the above-mentioned radio frame, the transmission of a signalusing the above-mentioned shared band by the device for performing thewireless LAN communication can be suppressed.

4.3. CONFIGURATION OF TERMINAL DEVICE

Next, an example of the configuration of a terminal device 200-2according to the second embodiment will be described with reference toFIG. 19. FIG. 19 is a block diagram illustrating the example of theconfiguration of the terminal device 200-2 according to the secondembodiment. Referring to FIG. 19, the terminal device 200-2 includes anantenna unit 210, a wireless communication unit 220, a storage unit 230,and a processing unit 250.

Here, the description of the antenna unit 210, the wirelesscommunication unit 220, and the storage unit 230 is not differentbetween the first embodiment and the second embodiment except for adifference of reference signs. Consequently, here, only the processingunit 250 will be described and redundant description will be omitted.

(Processing Unit 250)

The processing unit 250 provides various functions of the terminaldevice 200-2. The processing unit 250 includes a communication controlunit 251. Also, the processing unit 250 can further include anothercomponent in addition to the communication control unit 251.

(Communication Control Unit 251)

The communication control unit 251 controls the terminal device 200-1.

4.4. FLOW OF PROCESS

Next, an example of the process according to the second embodiment willbe described with reference to FIGS. 20 and 21.

FIRST EXAMPLE

FIG. 20 is a flowchart illustrating the first example of a schematicflow of the process according to the second embodiment. The process isan example of when a signal is transmitted as illustrated in FIG. 17.

The processing unit 160 (the communication control unit 161 or anothercomponent) determines whether a signal is transmitted using theabove-mentioned shared band on the basis of a result of receiving asignal by the wireless communication unit 120 (S401). When it isdetermined that the signal is transmitted using the above-mentionedshared band (S401: YES), the process returns to step S401.

On the other hand, when it is determined that no signal is transmittedusing the above-mentioned shared band (S401: NO), for example, thecommunication control unit 161 determines whether a period in which nosignal is transmitted using the above-mentioned shared band has become apredetermined period longer than the SIFS and shorter than the DIFS(S403). When it is determined that the above-mentioned period has notbecome the above-mentioned predetermined period (that is, a signal istransmitted using the above-mentioned shared band before the passage ofthe above-mentioned predetermined period) (S403: NO), the processreturns to step S401.

When it is determined that the above-mentioned period is theabove-mentioned predetermined period (S403: YES), the base station 100-2transmits and/or receives a signal using the above-mentioned shared bandaccording to control by the processing unit 160 (S405). The processends.

SECOND EXAMPLE

FIG. 21 is a flowchart illustrating the second example of a schematicflow of the process according to the second embodiment. The process isan example of when a signal is transmitted as illustrated in FIG. 18(and FIG. 17).

The processing unit 160 (the communication control unit 161 or anothercomponent) determines whether a signal is transmitted using theabove-mentioned shared band on the basis of a result of receiving thesignal by the wireless communication unit 120 (S411). When it isdetermined that the signal is transmitted using the above-mentionedshared band (S411: YES), the process returns to step S411.

On the other hand, when it is determined that no signal is transmittedusing the above-mentioned shared band (S411: NO), for example, thecommunication control unit 161 determines whether a period in which nosignal is transmitted using the above-mentioned shared band has become apredetermined period longer than the SIFS and shorter than the DIFS(S413). When it is determined that the above-mentioned period does notbecome the above-mentioned predetermined period (that is, a signal istransmitted using the above-mentioned shared band before the passage ofthe above-mentioned predetermined period) (S413: NO), the processreturns to step S411.

When it is determined that the above-mentioned period becomes theabove-mentioned predetermined period (S413: YES), the base station 100-2transmits a dummy signal using the above-mentioned shared band during aperiod until a radio frame for another frequency band for the cellularsystem 1 starts according to control by the processing unit 160 (S415).

Further, the base station 100-2 transmits and/or receives a signal of acellular system in a radio frame using the above-mentioned shared band(S417). The process ends.

4.5. FIRST MODIFIED EXAMPLE

(Summary)

(a) First Control for Securing Shared Band

In the above-mentioned example of the second embodiment, for example,the base station 100-2 starts to transmit a signal using theabove-mentioned shared band, for example, before the period in which nosignal is transmitted using the shared band becomes a DIFS.

On the other hand, in the first modified example of the secondembodiment, for example, the base station 100-2 controls the terminaldevice 200-2 so that the terminal device 200-2 starts to transmit asignal using the above-mentioned shared band before the period in whichno signal is transmitted using the shared band becomes the DIFS. Theterminal device 200-2 starts to transmit a signal using the shared bandbefore the period in which no signal is transmitted using the sharedband becomes the DIFS.

Thereby, for example, a device which does not receive a signaltransmitted by the base station 100-2 can also receive a signaltransmitted by the terminal device 200-2. Thus, for example, the hiddenterminal problem can be solved.

Also, even in the first modified example of the second embodiment, thebase station 100-2 (communication control unit 161) may start totransmit a signal using the above-mentioned shared band before theperiod in which no signal is transmitted using the shared band becomesthe DIFS.

(b) Second Control for Securing Shared Band

In the above-mentioned example of the second embodiment, for example,the base station 100-2 transmits a dummy signal using theabove-mentioned shared band during a period until a radio frame foranother frequency band to be used in the wireless communication of thecellular system 1 starts.

On the other hand, in the first modified example of the secondembodiment, for example, the base station 100-2 controls the terminaldevice 200-2 so that the terminal device 200-2 transmits a dummy signalusing the shared band during a period until a radio frame for anotherfrequency band to be used for the cellular communication starts. Theterminal device 200-2 transmits the dummy signal using theabove-mentioned shared band during the period until the radio frame forthe other frequency band to be used for the wireless communication ofthe cellular system 1 starts.

Thereby, for example, a device which does not receive a signaltransmitted by the base station 100-2 can also receive a signaltransmitted by the terminal device 200-2. Thus, for example, the hiddenterminal problem can be solved.

Also, even in the first modified example of the second embodiment, thebase station 100-2 (communication control unit 161) may transmit a dummysignal using the above-mentioned shared band during the period until theradio frame for the other frequency band to be used for the wirelesscommunication of the cellular system 1 starts.

(Base Station 100-2: Communication Control Unit 161)

(a) First Control for Securing Shared Band

As described above, for example, the communication control unit 161controls a wireless communication device for performing theabove-mentioned cellular communication so that the above-mentionedwireless communication device starts to transmit a signal using theabove-mentioned shared before a period in which no signal is transmittedusing the shared band becomes a DIFS. Further, for example, thecommunication control unit 161 controls the above-mentioned wirelesscommunication device so that the above-mentioned wireless communicationdevice starts to transmit a signal using the above-mentioned shared bandafter the period in which no signal is transmitted using the shared bandis longer than an SIFS.

In the first modified example, for example, the above-mentioned wirelesscommunication device is the terminal device 200-2 and the communicationcontrol unit 161 controls the terminal device 200-2 so that the terminaldevice 200-2 starts to transmit a signal using the above-mentionedshared band after the period in which no signal is transmitted using theshared band is longer than the SIFS and before the period becomes theDIFS. More specifically, for example, the communication control unit 161instructs the terminal device 200-2 to start the transmission of asignal using the above-mentioned shared band after the period in whichno signal is transmitted using the above-mentioned shared band is longerthan the SIFS and before the period becomes the DIFS. For example, thisinstruction can be performed according to RRC signaling or systeminformation.

(b) Second Control for Securing Shared Band

Transmission of Signal Until Start of Frame for Other Frequency Band

As described above, for example, the communication control unit 161controls a wireless communication device for performing theabove-mentioned cellular communication so that the above-mentionedwireless communication device transmits a dummy signal using the sharedband during a period until a radio frame for another frequency band tobe used in cellular communication starts.

In a first modified example, for example, the above-mentioned wirelesscommunication device is the terminal device 200-2. Also, for example,the above-mentioned shared band may be a CC for the cellular system 1and the above-mentioned other frequency band may be another CC for thecellular system 1. The communication control unit 161 may control theterminal device 200-2 so that the terminal device 200-2 transmits thedummy signal using the shared band (CC) during a period until the radioframe for the other CC starts. More specifically, for example, thecommunication control unit 161 instructs the terminal device 200-2 totransmit a dummy signal using the shared band (CC) during the perioduntil the radio frame for the other CC starts. For example, thisinstruction can be performed according to RRC signaling or systeminformation.

Transmission of Radio Frame for Setting NAV

As described above, in place of the transmission of the above-mentioneddummy signal, the communication control unit 161 may control theabove-mentioned wireless communication device so that theabove-mentioned wireless communication device transmits a frameincluding duration information for setting the NAV using theabove-mentioned shared band before the radio frame for theabove-mentioned frequency band starts.

In the first modified example, the above-mentioned wirelesscommunication device may be the terminal device 200-2. Also, theabove-mentioned shared band may be a CC for the cellular system 1 andthe above-mentioned other frequency band may be another CC for thecellular system 1. Also, the above-mentioned frame may be an RTS frame,a CTS frame, or a frame similar thereto. The communication control unit161 may control the terminal device 200-2 so that the terminal device200-2 transmits the above-mentioned frame using the above-mentionedshared band before the radio frame for another CC starts. Morespecifically, for example, the communication control unit 161 mayinstruct the terminal device 200-2 to transmit the above-mentioned framebefore the radio frame for the other CC starts. For example, thisinstruction can be performed according to RRC signaling or systeminformation.

The base station 100-2 according to the first modified example of thesecond embodiment has been described above. Also, in the first modifiedexample of the second embodiment, the above-mentioned wirelesscommunication device may be the base station 100-2 and the terminaldevice 200-2. As in the above-mentioned example of the secondembodiment, the base station 100-2 may also transmit a signal.

(Terminal Device 200-2: Communication Control Unit 251)

(a) First Control for Securing Shared Band

In the first modified example of the second embodiment, for example, thecommunication control unit 251 controls the terminal device 200-2 sothat the terminal device 200-2 starts to transmit a signal using theabove-mentioned shared band, for example, before the period in which nosignal is transmitted using the shared band becomes a DIFS.

Further, for example, the communication control unit 251 controls theterminal device 200-2 so that the terminal device 200-2 starts totransmit a signal using the above-mentioned shared band after the periodin which no signal is transmitted using the shared band is longer thanan SIFS.

For example, the communication control unit 251 controls the terminaldevice 200-2 according to an instruction by the base station 100-2. Morespecifically, for example, the processing unit 250 (the communicationcontrol unit 251 or another component) determines whether a signal istransmitted using the above-mentioned shared band on the basis of aresult of receiving a signal by the wireless communication unit 220.Also, the processing unit 250 (the communication control unit 251 oranother component) measures a period in which no signal is transmittedusing the above-mentioned shared band. The communication control unit251 causes the wireless communication unit 220 to transmit a signalusing the above-mentioned shared band after the period in which nosignal is transmitted using the shared band is longer than the SIFS andbefore the period becomes the DIFS. As an example, a signal istransmitted using the above-mentioned shared band when theabove-mentioned period becomes a predetermined period longer than theSIFS and shorter than the DIFS. Even in the first modified example ofthe second embodiment, the terminal device 200-2 transmits a signal, forexample, as illustrated in FIG. 17.

(b) Second Control for Securing Shared Band

Transmission of Signal Until Start of Frame for Other Frequency Band

In the first modified example of the second embodiment, for example, thecommunication control unit 251 controls the terminal device 200-2 sothat the terminal device 200-2 transmits a dummy signal using the sharedband during a period until a radio frame for another frequency band tobe used in cellular communication starts.

For example, the communication control unit 251 controls the terminaldevice 200-2 according to an instruction by the base station 100-2.Specifically, for example, the communication control unit 251 causes thewireless communication unit 220 to transmit a dummy signal during aperiod until a radio frame for another CC starts from a timing beforethe passage of the DIFS after the passage of the SIFS. Even in the firstmodified example of the second embodiment, for example, as illustratedin FIG. 18, the terminal device 200-2 transmits a signal.

Transmission of Radio Frame for Setting NAV

Also, in the first modified example of the second embodiment, in placeof the transmission of the above-mentioned dummy signal, thecommunication control unit 251 may control the terminal device 200-2 sothat the terminal device 200-2 transmits a frame including durationinformation for setting the NAV using the above-mentioned shared bandbefore the radio frame for the above-mentioned other frequency bandstarts.

For example, the communication control unit 251 may control the terminaldevice 200-2 according to an instruction by the base station 100-2.Specifically, for example, the communication control unit 251 maygenerate the above-mentioned frame and cause the wireless communicationunit 220 to transmit the above-mentioned frame before the radio framefor the other CC starts.

(Flow of Process)

An example of the process of the terminal device 200-2 according to thefirst modified example of the second embodiment is the same as theexample of the process of the base station 100-2 described withreference to FIGS. 20 and 21, except for the differences related to themain components (the base station 100-2 and the terminal device 200-2).Consequently, here, redundant description will be omitted.

4.6. SECOND MODIFIED EXAMPLE

(Summary)

As in the first modified example of the second embodiment, even in thesecond modified example of the second embodiment, for example, theterminal device 200-2 starts to transmit a signal using theabove-mentioned shared band before the period in which no signal istransmitted using the shared band becomes a DIFS. Also, for example, theterminal device 200-2 transmits a dummy signal using the above-mentionedshared band during a period until a radio frame for another frequencyband to be used in cellular communication starts.

In particular, in the second modified example of the second embodiment,the terminal device 200-2 independently transmits a signal using theabove-mentioned shared band as described above without depending uponcontrol by the base station 100-2 (an instruction by the base station100-2).

Thereby, for example, it is possible to more reliably secure theabove-mentioned shared band for the wireless communication between theterminal devices in the cellular system 1 (D2D communication in thecellular system or wireless communication within the LN).

(Terminal Device 200-2: Communication Control Unit 251)

The description of the communication control unit 251 according to thesecond modified example is the same as the description of thecommunication control unit 251 according to the first modified example,except for the difference related to the involvement of the base station100-2. Consequently, here, redundant description will be omitted.

Also, the communication control unit 251 according to the secondmodified example controls the terminal device 200-2 independently (forexample, according to a determination of whether to perform wirelesscommunication between the terminal devices in the cellular system 1using the shared band) without depending upon an instruction by the basestation 100-2.

(Flow of Process)

An example of the process of the terminal device 200-2 according to thesecond modified example of the second embodiment is the same as theexample of the process of the base station 100-2 described withreference to FIGS. 20 and 21, except for the differences related to themain components (the base station 100-2 and the terminal device 200-2).Consequently, here, redundant description will be omitted.

4.7. COMBINATION OF SECOND EMBODIMENT AND FIRST EMBODIMENT

The second embodiment may be combined with the above-mentioned firstembodiment. For example, an operation according to the second embodimentmay be applied to the above-mentioned first embodiment.

For example, the communication control unit 151 of the base station100-1 may further perform an operation of the communication control unit161 of the base station 100-2 and the communication control unit 241 ofthe terminal device 200-1 may further perform an operation of thecommunication control unit 251 of the terminal device 200-2.

Specifically, a technique according to the second embodiment may beused, for example, when the shared band is occupied for cellularcommunication during the first period in the first embodiment.Specifically, for example, when the wireless communication device (forexample, the base station 100 or the terminal device 200) for performingthe cellular communication transmits a signal using the shared bandduring the first period, a signal may start to be transmitted using theabove-mentioned shared band before a period in which no signal istransmitted using the shared band becomes a DIFS. Also, for example,when the wireless communication device (for example, the base station100 or the terminal device 200) for performing cellular communicationtransmits a signal using the shared band during the first period, adummy signal may be transmitted using the shared band during a perioduntil a radio frame of another frequency band starts. Thereby, forexample, it is possible to more reliably secure the shared band.

5. THIRD EMBODIMENT

Next, the third embodiment of the present disclosure will be describedwith reference to FIGS. 22 to 30.

5.1. SUMMARY

First, the summary of the third embodiment will be described.

Problem According to Third Embodiment

For example, a device for performing wireless LAN communication cantransmit a signal (for example, a signal of an RTS frame) using afrequency band (channel) when a period in which no signal is transmittedusing the frequency band reaches a sum of a DIFS and a backoff time. Forexample, the DIFS is shorter than a symbol of LTE (an OFDM symbol or anSC-FDMA symbol).

For example, a frequency band (for example, a channel of a wireless LAN)is shared between the cellular communication and the wireless LANcommunication. In this case, for example, it may be impossible totransmit any signal of the cellular system using the above-mentionedfrequency band in any symbol even while the above-mentioned frequencyband is used in the cellular communication. Thus, the device forperforming the wireless LAN communication is likely to transmit a signal(for example, a signal of an RTS frame) using the above-mentionedfrequency band even while the above-mentioned frequency band is used incellular communication. Thus, the interference between the cellularcommunication and the wireless LAN communication occurs in theabove-mentioned frequency band and the communication quality of theabove-mentioned cellular communication and/or the above-mentioned otherwireless communication is likely to deteriorate.

Therefore, it is desirable to provide a mechanism for enabling thefrequency band shared between the cellular communication and the otherwireless communication to be more appropriately used in the cellularsystem. More specifically, it is desirable to provide a mechanismcapable of preventing the above-mentioned frequency band from being usedin the above-mentioned other wireless communication while the frequencyband shared between the cellular communication and the other wirelesscommunication (for example, wireless LAN communication) is used in thecellular communication.

Characteristics of Third Embodiment

According to the third embodiment, at any time, a wireless communicationdevice for performing cellular communication is controlled so that theabove-mentioned wireless communication device transmits a signal using afrequency band shared between the cellular communication and otherwireless communication (that is, a shared band). Thereby, for example,it is possible to prevent the above-mentioned frequency band from beingused in the above-mentioned other wireless communication while thefrequency band shared between the cellular communication and the otherwireless communication (for example, wireless LAN communication) is usedin the cellular communication.

5.2. CONFIGURATION OF BASE STATION

Next, an example of the configuration of a base station 100-3 accordingto the third embodiment will be described with reference to FIGS. 22 to27. FIG. 22 is a block diagram illustrating an example of theconfiguration of the base station 100-3 according to the thirdembodiment. Referring to FIG. 22, the base station 100-3 is equippedwith an antenna unit 110, a wireless communication unit 120, a networkcommunication unit 130, a storage unit 140, and a processing unit 170.

Here, the description of the antenna unit 110, the wirelesscommunication unit 120, the network communication unit 130, and thestorage unit 140 is not different between the first embodiment and thethird embodiment, except for a difference of reference signs.Consequently, here, only the processing unit 170 will be described andredundant description will be omitted.

(Processing Unit 170)

The processing unit 170 provides various functions of the base station100-3. The processing unit 170 includes a communication control unit171. Also, the processing unit 170 can further include another componentin addition to the communication control unit 171.

(Communication Control Unit 171)

The communication control unit 171 controls a wireless communicationdevice for performing the cellular communication so that theabove-mentioned wireless communication device transmits a signal usingthe above-mentioned shared at any time. The above-mentioned shared bandis a frequency band shared between wireless communication (that is, acellular communication) of the cellular system 1 and other wirelesscommunication.

(a) Other Wireless Communication

For example, the above-mentioned wireless communication is wirelesscommunication (that is, wireless LAN communication) conforming to awireless LAN standard. In this case, the above-mentioned shared band isshared between the cellular communication and the wireless LANcommunication. The above-mentioned shared band is, for example, achannel of a wireless LAN.

(b) Unit of Time

The communication control unit 171 controls the above-mentioned wirelesscommunication device so that the above-mentioned wireless communicationdevice transmits a signal using the above-mentioned shared band in eachsymbol. The above-mentioned symbol is, for example, an OFDM symbol or anSC-FDMA symbol. Thereby, for example, it is possible to eliminate anon-signal time.

(c) Wireless Communication Device

The above-mentioned wireless communication device is at least one of thebase station 100-3 and the terminal device 200-3.

Case of FDD

Downlink Band

As a first example, the FDD is adopted in the cellular system 1 and theabove-mentioned shared band is used as the downlink band in the cellularsystem 1. In this case, the above-mentioned wireless communicationdevice is the base station 100-3. That is, the communication controlunit 171 controls the base station 100-3 so that the base station 100-3transmits a signal using a shared band (downlink band) at any time.

Specifically, for example, the communication control unit 171 maps asignal to one or more resource elements within the above-mentionedshared band in each symbol. Thereby, the base station 100-3 transmitsthe signal using the above-mentioned shared band in each symbol.

Uplink Band

As a second example, the FDD is adopted in the cellular system 1 and theabove-mentioned shared band is used as the uplink band in the cellularsystem 1. In this case, the above-mentioned wireless communicationdevice is a terminal device 200-3. That is, the communication controlunit 171 controls the terminal device 10 200-3 so that the base station100-3 transmits a signal using the above-mentioned shared band (uplinkband) at any time.

Specifically, for example, the communication control unit 171 instructsthe terminal device 200-3 to transmit a signal using the above-mentionedshared band at any time for the uplink.

Thereby, for example, the terminal device 200-3 can transmit a signalusing the above-mentioned shared band at any time (in each symbol).Also, for example, this instruction can be performed according to RRCsignaling or system information.

Case of TDD

As a third example, the TDD is adopted in the cellular system 1 and theabove-mentioned shared band is used as the downlink and uplink bands inthe cellular system 1. In this case, the above-mentioned wirelesscommunication device is the base station 100-3 and the terminal device200-3.

For example, the communication control unit 171 controls the basestation 100-3 so that the base station 100-3 transmits a signal usingthe above-mentioned shared band at any downlink time. Specifically, forexample, the communication control unit 171 maps a signal to one or moreresource elements within the above-mentioned shared band in each symbolfor a downlink sub-frame. Thereby, the base station 100-3 transmits asignal using the above-mentioned shared band in each symbol within thedownlink sub-frame.

Also, for example, the communication control unit 171 controls theterminal device 200-3 so that the terminal device 200-3 transmits asignal using the above-mentioned shared band at any uplink time.Specifically, for example, the communication control unit 171 instructsthe terminal device 200-3 to transmit a signal using the above-mentionedshared band at any time for the uplink. Thereby, for example, theterminal device 200-3 can transmit a signal using the above-mentionedshared band at any uplink time (in each symbol within the uplinksub-frame). Also, for example, this instruction can be performedaccording to RRC signaling or system information.

(d) Transmission Power

For example, the communication control unit 171 controls theabove-mentioned wireless communication device so that transmission powerof a signal to be transmitted using the above-mentioned shared band isgreater than or equal to predetermined transmission power at any time.

For example, the above-mentioned wireless communication device is a basestation 100-3 and the communication control unit 171 controls the basestation 100-3 so that the transmission power of the signal to betransmitted using the above-mentioned shared band is greater than orequal to the predetermined transmission power at any time for thedownlink. Specifically, for example, the communication control unit 171allocates power greater than or equal to the above-mentionedpredetermined transmission power to the signal to be transmitted usingthe above-mentioned shared band in each symbol.

Also, for example, the above-mentioned wireless communication system isthe terminal device 200-3 and the communication control unit 171controls the terminal device 200-3 so that the transmission power of thesignal to be transmitted using the above-mentioned shared band isgreater than or equal to the predetermined transmission power at anytime for the uplink. Specifically, for example, the communicationcontrol unit 171 indicates the transmission power of a signal to betransmitted using the above-mentioned shared band to the terminal device200-3.

Thereby, for example, in a device for performing other wirelesscommunication (for example, wireless LAN communication), reception powerof the above-mentioned signal can reach desired power. As a result, thedevice can more reliably avoid the transmission of a signal using theabove-mentioned shared band.

(e) Technique of Transmission of Signal

Transmission of Dummy Signal

For example, the communication control unit 171 controls the basestation 100-3 so that the base station 100-3 transmits a dummy signalusing the above-mentioned shared band in at least a symbol in whichneither a data signal nor a control signal of the cellular system 1 istransmitted using the above-mentioned shared band. Thereby, for example,it is possible to reliably transmit a signal in each symbol of downlink.

Also, the above-mentioned dummy signal is, for example, any signal otherthan signals (a control signal and a data signal) of the cellularsystem. The above-mentioned dummy signal is a busy tone for a device forperforming wireless LAN communication.

Transmission of Dummy Signal in Some Radio Resources

For example, the communication control unit 171 controls the basestation 100-3 so that the base station 100-3 transmits theabove-mentioned dummy signal in some radio resources among radioresources arranged in a frequency direction across the above-mentionedshared band in at least the above-mentioned symbol.

Specifically, for example, the communication control unit 171 maps adummy signal to one or more resource elements (REs) within theabove-mentioned shared band in at least a symbol in which a data signaland a control signal are not transmitted.

Transmission in Some Resource Blocks (RBs)

For example, some radio resources mentioned above are some RBs among RBsarranged in a frequency direction across the above-mentioned sharedband. That is, the base station 100-3 transmits a dummy signal in someRBs among the RBs arranged in the frequency direction across theabove-mentioned shared band. Hereinafter, in this regard, a specificexample will be described with reference to FIGS. 23 and 24.

FIG. 23 is an explanatory diagram illustrating an example of some RBs inwhich a dummy signal is transmitted. Referring to FIG. 23, a shared band71 and RBs arranged across a plurality of slots are illustrated. In thisexample, a dummy signal is transmitted in one specific RB among the RBsarranged in the frequency direction across the shared band 71 withineach slot. Also, no dummy signal is transmitted in the other RBs.

FIG. 24 is an explanatory diagram illustrating a first example of an REin which a dummy signal is transmitted. Referring to FIG. 24, one ofsome RBs in which the dummy signal (for example, illustrated in FIG. 23)is transmitted is illustrated. In this example, the dummy signal istransmitted in all REs other than a cell-specific reference signal (CRS)RE among REs included in the RB.

Thereby, for example, it is possible to allocate an RB in which no dummysignal is transmitted. Consequently, backward compatibility can be moreeasily secured.

Also, the dummy signal is transmitted in only one RB in the example ofFIG. 30 23, but, of course, the dummy signal may be transmitted in twoor more RBs. Also, an RB band in which the dummy signal is transmittedis common between slots in the example of FIG. 23, but, of course, theRB band in which the dummy signal is transmitted may be differentbetween slots.

Also, the dummy signal is transmitted in all REs except for a CRS RE inthe RB in the example of FIG. 24, but, of course, the dummy signal maybe transmitted in some REs in the RB. As an example, no dummy signal maybe transmitted in one or more sub-carriers among 12 sub-carriers of theRB. As another example, no dummy signal may be transmitted in one ormore symbols in which another signal is transmitted. As a specificexample, no dummy signal may be transmitted in one or more symbols (thatis, first to third OFDM symbols in a first slot of a sub-frame) in whichsignals of control channels such as a PDCCH and a PCFICH aretransmitted. Also, as still another specific example, no dummy signalmay be transmitted in one or more symbols in which a data signal istransmitted.

Transmission in each RB

Also, some radio resources mentioned above may be some REs included ineach RB arranged in the frequency direction across the above-mentionedshared band. That is, the base station 100-3 may transmit a dummy signalin some REs included in each RB arranged in the frequency directionacross the above-mentioned shared band. Hereinafter, in this regard, aspecific example will be described with reference to FIG. 25.

FIG. 25 is an explanatory diagram illustrating a second example of an REin which a dummy signal is transmitted. Referring to FIG. 25, an RB whena dummy signal is transmitted in each RB is illustrated. In thisexample, the dummy signal is transmitted in one or two specific REsamong 12 REs arranged in the frequency direction across an RB withineach symbol. Also, no dummy signal is transmitted in other REs.

Also, a dummy signal is transmitted in only REs of two sub-carriers inthe example of FIG. 25, but, of course, the dummy signal may betransmitted in an RE of one sub-carrier or may be transmitted in REs ofthree or more sub-carriers. Also, a sub-carrier of an RE in which thedummy signal is transmitted is common between symbols in the example ofFIG. 25, but, of course, the sub-carrier of the RE in which the dummysignal is transmitted may be different between symbols. Also, no dummysignal may be transmitted in one or more symbols in which another signalis transmitted among seven symbols of an RB. As a specific example, nodummy signal may be transmitted in one or more symbols (that is, firstto third OFDM symbols of a first slot of a sub-frame) in which signalsof control channels such as the PDCCH and the PCFICH are transmitted. Asanother specific example, no dummy signal may be transmitted in one ormore symbols in which the data signal is transmitted.

(f) Transmission of Signal by Plurality of Terminal Devices

Instruction for Plurality of Terminal Devices

For example, the communication control unit 171 instructs each of theplurality of terminal devices 200-3 to transmit a signal using theabove-mentioned shared band at any time for the uplink. For example,this instruction can be performed according to RRC signaling or systeminformation.

Thereby, for example, because the plurality of terminal devices 200-3transmit signals, the signals reach a wider area. Thus, the transmissionof a signal using the above-mentioned shared band by the device forperforming other wireless communication (for example, wireless LANcommunication) can be more reliably suppressed.

Radio Resource for Transmitting Dummy Signal

Also, for example, the communication control unit 171 instructs aplurality of terminal devices to transmit the above-mentioned dummysignal in some radio resources among radio resources arranged in afrequency direction across the above-mentioned shared band in at least asymbol in which neither a data signal nor a control signal of thecellular system 1 is transmitted using the above-mentioned shared bandfor the uplink.

Specifically, for example, the communication control unit 171 instructsthe plurality of terminal devices to transmit the dummy signal. Also,the communication control unit 171 designates a radio resource fortransmitting the dummy signal at the time of such an instruction.

Common Radio Resource

Some radio resources mentioned above are common among a plurality ofterminal devices 200-3. That is, the communication control unit 171instructs the plurality of terminal devices 200-3 to transmit theabove-mentioned dummy signals in a common radio resource among theabove-mentioned plurality of terminal devices 200-3 in at least theabove-mentioned symbol for the uplink. Hereinafter, a specific exampleof the radio resource will be described with reference to FIG. 26.

FIG. 26 is an explanatory diagram illustrating a first example of radioresources in which dummy signals are transmitted by the plurality ofterminal devices 200-3. Referring to FIG. 26, a shared band 71 and RBsarranged across a plurality of slots are illustrated. In this example,the plurality of terminal devices 200-3 transmit the dummy signals inthe same RB among the RBs arranged in the frequency direction across theshared band 71 within each slot.

Thereby, for example, in the cellular system 1, it is possible toallocate more RBs in which no dummy signal is transmitted.

Separate Radio Resources

Also, some radio resources mentioned above may be different between atleast two of the plurality of terminal devices 200-3. That is, thecommunication control unit 171 may instruct the at least two of theplurality of terminal devices 200-3 to transmit the above-mentioneddummy signals in different radio resources. Hereinafter, a specificexample of the radio resource will be described with reference to FIG.27.

FIG. 27 is an explanatory diagram illustrating a second example of radioresources in which dummy signals are transmitted by the plurality ofterminal devices 200-3. Referring to FIG. 27, a shared band 71 and RBsarranged across a plurality of slots are illustrated. In this example,first to third terminal devices 200-3 transmit dummy signals indifferent RBs among the RBs arranged in the frequency direction acrossthe shared band 71 within each slot.

As described above, the communication control unit 171 controls awireless communication device for performing the cellular communicationso that the above-mentioned wireless communication device transmits asignal using the shared band at any time. Thereby, for example, while afrequency band shared between the cellular communication and otherwireless communication (for example, wireless LAN communication) (thatis, a shared band) is used in the cellular communication, it is possibleto prevent the above-mentioned frequency band from being used in theabove-mentioned other wireless communication. Also, according to thistechnique, for example, a wireless LAN communication device which cannotset the NAV can be prevented from using the above-mentioned frequencyband (that is, the shared band).

5.3. CONFIGURATION OF BASE STATION

Next, an example of the configuration of terminal device 200-3 accordingto the third embodiment will be described with reference to FIGS. 28.FIG. 28 is a block diagram illustrating an example of the configurationof the terminal device 200-3 according to the third embodiment.Referring to FIG. 28, the terminal device 200-3 is equipped with anantenna unit 210, a wireless communication unit 220, a storage unit 230,and a processing unit 260.

Here, the description of the antenna unit 210, the wirelesscommunication unit 220, and the storage unit 230 is not differentbetween the first embodiment and the third embodiment, except for adifference of reference signs. Consequently, here, only the processingunit 260 will be described and redundant description will be omitted.

(Processing Unit 260)

The processing unit 260 provides various functions of the terminaldevice 200-3. The processing unit 260 includes a communication controlunit 261. Also, the processing unit 260 can further include anothercomponent in addition to the communication control unit 261.

(Communication Control Unit 261)

The communication control unit 261 controls the terminal device 200-3 sothat the terminal device 200-3 transmits a signal using a shared band atany time for the uplink. The above-mentioned shared band is a frequencyband to be shared between cellular communication and other wirelesscommunication.

Also, the above-mentioned frequency band is an uplink band when an FDDis adopted or downlink and uplink bands when a TDD is adopted.

(a) Other Wireless Communication and Unit of Time

For example, the above-mentioned other wireless communication iswireless communication (that is, wireless LAN communication) conformingto the wireless LAN standard.

Also, for example, the communication control unit 261 controls theterminal device 200-3 so that the terminal device 200-3 transmits asignal using the above-mentioned shared band in each symbol. Theabove-mentioned symbol is, for example, an SC-FDMA symbol.

(b) Trigger of Control

For example, the communication control unit 261 controls the terminaldevice 200-3 so that the terminal device 200-3 transmits a signal usinga shared band at any time according to an instruction by the basestation 100-3.

(c) Transmission Power

For example, the communication control unit 261 controls the terminaldevice 200-3 so that transmission power of a signal to be transmittedusing the above-mentioned shared band is greater than or equal topredetermined transmission power at any time. Specifically, for example,the communication control unit 261 allocates power greater than or equalto the above-mentioned predetermined transmission power to a signal tobe transmitted using the above-mentioned shared band in each symbol.Also, for example, the predetermined transmission power is indicated bythe base station 100-3.

Thereby, for example, in a device for performing other wirelesscommunication (for example, wireless LAN communication), reception powerof the above-mentioned signal can reach desired power. As a result, thedevice can reliably avoid the transmission of a signal using theabove-mentioned shared band.

(d) Technique of Transmission of Signal

Transmission of Dummy Signal

For example, the communication control unit 261 controls the terminaldevice 200-3 so that the terminal device 200-3 transmits a dummy signalusing the above-mentioned shared band in at least a symbol in whichneither a data signal nor a control signal of the cellular system 1 istransmitted using the above-mentioned shared band. Thereby, for example,it is possible to reliably transmit a signal in each symbol of uplink.

Also, the description of a specific technique of transmission of a dummysignal by the terminal device 200-3 is the same as the description ofthe specific technique of transmission of a dummy signal by the basestation 100-3 described above, except for a difference related to a linkdirection (downlink and uplink). Consequently, here, redundantdescription will be omitted.

As described above, the communication control unit 261 controls theterminal device 200-3 so that the terminal device 200-3 transmits asignal using the shared band at any time. Thereby, it is possible toprevent a frequency band shared between cellular communication and otherwireless communication (for example, wireless LAN communication) (thatis, a shared band) from being used in the above-mentioned other wirelesscommunication, for example, while the above-mentioned frequency band isused in the uplink communication.

5.4 FLOW OF PROCESS

Next, an example of a process according to the third embodiment will bedescribed with reference to FIGS. 29 and 30.

(Process by Base Station)

FIG. 29 is a flowchart illustrating an example of a schematic flow of aprocess by the base station 100-3 according to the third embodiment.

The communication control unit 171 selects a target symbol (S501).

The communication control unit 171 maps a dummy signal to some radioresources among radio resources arranged in the frequency directionacross the shared band for the target symbol (S503).

When cellular communication using the shared band has been terminated(S505: YES), the process ends. Otherwise (S505: NO), the communicationcontrol unit 171 selects the next symbol as the target symbol (S501).

(Process by Terminal Device)

FIG. 30 is a flowchart illustrating an example of a schematic flow of aprocess by the terminal device 200-3 according to the third embodiment.The process is executed by the terminal device 200-3 according to aninstruction by the base station 100-3.

The communication control unit 261 selects a target symbol (S511).

The communication control unit 261 maps a dummy signal to some radioresources among radio resources arranged in the frequency directionacross the shared band for the target symbol (S513).

When the cellular communication using the shared band has beenterminated (S515: YES), the process ends. Otherwise (S515: NO), thecommunication control unit 261 selects the next symbol as the targetsymbol (S511).

5.5. MODIFIED EXAMPLE

(Summary)

In the above-mentioned example of the third embodiment, for example, thebase station 100-3 instructs the terminal device 200-3 to transmit asignal using a shared band (for example, in each symbol) at any time forthe uplink. Also, for example, the terminal device 200-3 transmits asignal using the shared band (for example, in each symbol) at any timeaccording to an instruction by the base station 100-3.

On the other hand, in the modified example of the third embodiment, theterminal device 200-3 transmits a signal using the shared band at anytime (for example, in each symbol) independently without depending uponthe instruction by the base station 100-3.

Thereby, for example, while a frequency band shared between cellularcommunication and other wireless communication (that is, a shared band)is used in wireless communication between the terminal devices (forexample, D2D communication or wireless communication within the LN) inthe cellular system, the above-mentioned frequency band can be preventedfrom being used in the above-mentioned other wireless communication.

(Terminal Device 200-3: Communication Control Unit 261)

In the modified example of the third embodiment, the communicationcontrol unit 261 controls the terminal device 200-3 so that the terminaldevice 200-3 transmits a signal using the shared band at any time.

The description of the communication control unit 261 in this regard isthe same as the corresponding description for the communication controlunit 261 according to the above-mentioned third embodiment, except fordifferences related to the involvement of a base station and a linkdirection. Consequently, here, redundant description will be omitted.

Also, in the above-mentioned example of the third embodiment, forexample, the communication control unit 261 controls the terminal device200-3 so that the terminal device 200-3 transmits a signal using theshared band at any time according to an instruction by the base station100-3. On the other hand, in the modified example of the thirdembodiment, the communication control unit 261 20 controls the terminaldevice 200-3 so that the terminal device 200-3 transmits a signal usingthe shared band at any time independently (for example, in a period inwhich the shared band is used in the cellular communication).

Also, in the above-mentioned example of the third embodiment, forexample, the communication control unit 261 controls the terminal device200-3 so that the terminal device 200-3 transmits a signal using theshared band at any time for the uplink. On the other hand, in themodified example of the third embodiment, for example, the communicationcontrol unit 261 controls the terminal device 200-3 so that the terminaldevice 200-3 transmits a signal using a shared band at any time duringwireless communication between the terminal devices in the cellularsystem 1.

(Flow of Process)

An example of the process of the terminal device 200-3 according to themodified example of the third embodiment is the same as the example ofthe process of the terminal device 200-3 described with reference toFIG. 30. Consequently, here, redundant description will be omitted.

5.6. COMBINATION OF THIRD EMBODIMENT AND FIRST EMBODIMENT/SECONDEMBODIMENT

(Combination of Third Embodiment and First Embodiment)

The third embodiment may be combined with the above-mentioned firstembodiment. For example, an operation according to the third embodimentmay be applied to the above-mentioned first embodiment.

For example, the communication control unit 151 of the base station100-1 15 may further perform an operation of the communication controlunit 171 of the base station 100-3 and the communication control unit241 of the terminal device 200-1 may further perform an operation of thecommunication control unit 261 of the terminal device 200-3.

Specifically, a technique according to the third embodiment may be used,for example, when a shared band is occupied for cellular communicationduring a first period in the first embodiment. Specifically, forexample, the wireless communication device (for example, the basestation 100 or the terminal device 200) for performing the cellularcommunication may transmit a signal using the shared band at any time(for example, in each symbol) during the first period. Thereby, forexample, the use of the shared band for other wireless communication(for example, wireless LAN communication) is prevented during the firstperiod. Consequently, the shared band can be more reliably occupied forthe cellular communication.

(Combination of Third Embodiment and Second Embodiment>

The third embodiment may be combined with the above-mentioned secondembodiment. For example, an operation according to the third embodimentmay be applied to the above-mentioned second embodiment.

For example, the communication control unit 161 of the base station100-2 may further perform an operation of the communication control unit171 of the base station 100-3 and the communication control unit 251 ofthe terminal device 200-2 may further perform an operation of thecommunication control unit 261 of the terminal device 200-3.

Specifically, a technique according to the third embodiment may be used,for example, when a signal is transmitted using a shared band in thesecond embodiment. Specifically, for example, the wireless communicationdevice (for example, the base station 100 or the terminal device 200)for performing the cellular communication may start to transmit a signalusing the shared band before a period in which no signal is transmittedusing the shared band becomes a DTFS and then transmit a signal usingthe shared band (for example, in each symbol) at any time (during anyperiod). Thereby, for example, it is possible to more reliably securethe shared band and then continuously use the shared band in thecellular communication.

Also, of course, all the first to third embodiments may be combined.

6. APPLICATIONS

Technology according to the present disclosure is applicable to variousproducts. For example, the base station 100 may be implemented as a typeof eNB such as a macro eNB or a small eNB. The small eNB may be an eNBto cover a cell smaller than a macro cell such as a pico eNB, a microeNB, or a home (femto) eNB. Conversely, the base station 100 may also berealized as another type of base station, such as a NodeB or a basetransceiver station (BTS). The base station 100 may also include a mainunit that controls wireless communication (also called a base stationdevice), and one or more remote radio heads (RRHs) placed in a locationseparate from the main unit. Also, various types of terminals to bedescribed below temporarily or semi-permanently execute a base stationfunction and therefore may operate as the base station 100.

In addition, the terminal device 200 may be realized as, for example, amobile terminal such as a smartphone, a tablet personal computer (PC), anotebook PC, a portable game console, a portable/dongle-style mobilerouter, or a digital camera, or as an in-vehicle terminal such as a carnavigation device. In addition, the terminal device 200 may also berealized as a terminal that conducts machine-to-machine (M2M)communication (also called a machine-type communication (MTC) terminal).Furthermore, at least a part of constituent elements of the terminaldevice 200 may be realized as a module mounted onboard these terminals(for example, an integrated circuit module configured on a single die).

6.1. APPLICATION EXAMPLES REGARDING BASE STATION FIRST APPLICATIONEXAMPLE

FIG. 31 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 may be connected to each other via an RF cable.

Each of the antennas 810 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the base station device 820 to transmit and receive radiosignals. The eNB 800 may include the multiple antennas 810, asillustrated in FIG. 31. For example, the multiple antennas 810 may becompatible with multiple frequency bands used by the eNB 800. AlthoughFIG. 31 illustrates the example in which the eNB 800 includes themultiple antennas 810, the eNB 800 may also include a single antenna810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of a higher layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in signalsprocessed by the wireless communication interface 825, and transfers thegenerated packet via the network interface 823. The controller 821 maybundle data from multiple base band processors to generate the bundledpacket, and transfer the generated bundled packet. The controller 821may have logical functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. The control may be performed in corporation with an eNBor a core network node in the vicinity. The memory 822 includes RAM andROM, and stores a program that is executed by the controller 821, andvarious types of control data (such as a terminal list, transmissionpower data, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In that case, the eNB 800, and the core network node orthe other eNB may be connected to each other through a logical interface(such as an S1 interface and an X2 interface). The network interface 823may also be a wired communication interface or a wireless communicationinterface for radio backhaul. If the network interface 823 is a wirelesscommunication interface, the network interface 823 may use a higherfrequency band for wireless communication than a frequency band used bythe wireless communication interface 825.

The wireless communication interface 825 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides radioconnection to a terminal positioned in a cell of the eNB 800 via theantenna 810. The wireless communication interface 825 may typicallyinclude, for example, a baseband (BB) processor 826 and an RF circuit827. The BB processor 826 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing of layers (such as L1, medium accesscontrol (MAC), radio link control (RLC), and a packet data convergenceprotocol (PDCP)). The BB processor 826 may have a part or all of theabove-mentioned logical functions instead of the controller 821. The BBprocessor 826 may be a memory that stores a communication controlprogram, or a module that includes a processor and a related circuitconfigured to execute the program. Updating the program may allow thefunctions of the BB processor 826 to be changed. The module may be acard or a blade that is inserted into a slot of the base station device820. Alternatively, the module may also be a chip that is mounted on thecard or the blade. Meanwhile, the RF circuit 827 may include, forexample, a mixer, a filter, and an amplifier, and transmits and receivesradio signals via the antenna 810.

The wireless communication interface 825 may include the multiple BBprocessors 826, as illustrated in FIG. 31. For example, the multiple BBprocessors 826 may be compatible with multiple frequency bands used bythe eNB 800. The wireless communication interface 825 may include themultiple RF circuits 827, as illustrated in FIG. 31. For example, themultiple RF circuits 827 may be compatible with multiple antennaelements. Although FIG. 31 illustrates the example in which the wirelesscommunication interface 825 includes the multiple BB processors 826 andthe multiple RF circuits 827, the wireless communication interface 825may also include a single BB processor 826 or a single RF circuit 827.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 825 may support a radio LANcommunication scheme. In that case, the wireless communication interface825 may include the BB processor 826 and the RF circuit 827 in the radioLAN communication scheme.

In the eNB 800 illustrated in FIG. 31, the communication control unit151 30 described with reference to FIG. 6 may be implemented in thewireless communication interface 825 (for example, the BB processor).Alternatively, at least a part of the communication control unit 151 maybe implemented in the controller 821. As one example, the eNB 800 isequipped with a module including a part (for example, the BB processor826) or all of the wireless communication interface 825 and/or thecontroller 821, and the communication control unit 151 may beimplemented in the module. In this case, the above-mentioned module maystore a program for causing the processor to function as thecommunication control unit 151 (in other words, a program for causingthe processor to execute the operation of the communication control unit151) and execute the program. As another example, a program for causingthe processor to function as the communication control unit 151 isinstalled in the eNB 800, and the wireless communication interface 825(for example, the BB processor 826) and/or the controller 821 mayexecute the program. As mentioned above, the eNB 800, the base stationdevice 820, or the above-mentioned module may be provided as the deviceincluding the communication control unit 151, and the program forcausing the processor to function as the communication control unit 151may be provided. Also, a readable storage medium storing theabove-mentioned program may be provided. With respect to these points,the communication control unit 161 described with reference to FIG. 16and the communication control unit 171 described with reference to FIG.22 are also similar to the communication control unit 151.

Also, in the eNB 800 illustrated in FIG. 31, the wireless communicationunit 120 described with reference to FIG. 6 may be implemented in thewireless communication interface 825 (for example, the RF circuit 827).Also, the antenna unit 110 may be implemented in the antenna 810. Also,the network communication unit 130 may be implemented in the controller821 and/or the network interface 823.

SECOND APPLICATION EXAMPLE

FIG. 32 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 830 includes one or more antennas 840,a base station device 850, and an RRH 860. Each antenna 840 and the RRH860 may be connected to each other via an RF cable. The base stationdevice 850 and the RRH 860 may be connected to each other via a highspeed line such as an optical fiber cable.

Each of the antennas 840 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the RRH 860 to transmit and receive radio signals. The eNB 830may include the multiple antennas 840, as illustrated in FIG. 32. Forexample, the multiple antennas 840 may be compatible with multiplefrequency bands used by the eNB 830. Although FIG. 32 illustrates theexample in which the eNB 830 includes the multiple antennas 840, the eNB830 may also include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are the same as the controller 821, the memory822, and the network interface 823 described with reference to FIG. 31.

The wireless communication interface 855 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides wirelesscommunication to a terminal positioned in a sector corresponding to theRRH 860 via the RRH 860 and the antenna 840. The wireless communicationinterface 855 may typically include, for example, a BB processor 856.The BB processor 856 is the same as the BB processor 826 described withreference to FIG. 31, except the BB processor 856 is connected to the RFcircuit 864 of the RRH 860 via the connection interface 857. Thewireless communication interface 855 may include the multiple BBprocessors 856, as illustrated in FIG. 32. For example, the multiple BBprocessors 856 may be compatible with multiple frequency bands used bythe eNB 830. Although FIG. 32 illustrates the example in which thewireless communication interface 855 includes the multiple BB processors856, the wireless communication interface 855 may also include a singleBB processor 856.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 855 may support a radio LANcommunication scheme. In that case, the wireless communication interface825 may include the BB processor 856 in the radio LAN communicationscheme.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may also be a communication module forcommunication in the above-mentioned high speed line that connects thebase station device 850 (wireless communication interface 855) to theRRH 860.

The RRH 860 includes a connection interface 861 and a wirelesscommunication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may also be a communication module forcommunication in the above-mentioned high speed line.

The wireless communication interface 863 transmits and receives radiosignals via the antenna 840. The wireless communication interface 863may typically include, for example, the RF circuit 864. The RF circuit864 may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives radio signals via the antenna 840. The wirelesscommunication interface 863 may include multiple RF circuits 864, asillustrated in FIG. 32. For example, the multiple RF circuits 864 maysupport multiple antenna elements. Although FIG. 32 illustrates theexample in which the wireless communication interface 863 includes themultiple RF circuits 864, the wireless communication interface 863 mayalso include a single RF circuit 864.

In the eNB 830 illustrated in FIG. 32, the communication control unit151 described with reference to FIG. 6 may be implemented in thewireless communication interface 855 (for example, the BB processor).Alternatively, at least a part of the communication control unit 151 maybe implemented in the controller 851. As one example, the eNB 830 isequipped with a module including a part (for example, the BB processor856) or all of the wireless communication interface 855 and/or thecontroller 851, and the communication control unit 151 may beimplemented in the module. In this case, the above-mentioned module maystore a program for causing the processor to function as thecommunication control unit 151 (in other words, a program for causingthe processor to execute the operation of the communication control unit151) and execute the program. As another example, a program for causingthe processor to function as the communication control unit 151 isinstalled in the eNB 830, and the wireless communication interface 855(for example, the BB processor 856) and/or the controller 851 mayexecute the program. As mentioned above, the eNB 830, the base stationdevice 850, or the above-mentioned module may be provided as the deviceincluding the communication control unit 151, and the program forcausing the processor to function as the communication control unit 151may be provided. Also, a readable storage medium storing theabove-mentioned program may be provided. With respect to these points,the communication control unit 161 described with reference to FIG. 16and the communication control unit 171 described with reference to FIG.22 are also similar to the communication control unit 151.

Also, in the eNB 830 illustrated in FIG. 32, the wireless communicationunit 120 described, for example, with reference to FIG. 6 may beimplemented in the wireless communication interface 863 (for example,the RF circuit 864). Also, the antenna unit 110 may be implemented inthe antenna 840. Also, the network communication unit 130 may beimplemented in the controller 851 and/or the network interface 853.

6.2. APPLICATION EXAMPLES REGARDING TERMINAL DEVICE FIRST APPLICATIONEXAMPLE

FIG. 33 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure may be applied. The smartphone 900 includes a processor 901,a memory 902, a storage 903, an external connection interface 904, acamera 906, a sensor 907, a microphone 908, an input device 909, adisplay device 910, a speaker 911, a wireless communication interface912, one or more antenna switches 915, one or more antennas 916, a bus917, a battery 918, and an auxiliary controller 919.

The processor 901 may be, for example, a CPU or a system on a chip(SoC), and controls functions of an application layer and another layerof the smartphone 900. The memory 902 includes RAM and ROM, and stores aprogram that is executed by the processor 901, and data. The storage 903may include a storage medium such as a semiconductor memory and a harddisk. The external connection interface 904 is an interface forconnecting an external device such as a memory card and a universalserial bus (USB) device to the smartphone 900.

The camera 906 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 907 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 908 converts soundsthat are input to the smartphone 900 to audio signals. The input device909 includes, for example, a touch sensor configured to detect touchonto a screen of the display device 910, a keypad, a keyboard, a button,or a switch, and receives an operation or an information input from auser. The display device 910 includes a screen such as a liquid crystaldisplay (LCD) and an organic light-emitting diode (OLED) display, anddisplays an output image of the smartphone 900. The speaker 911 convertsaudio signals that are output from the smartphone 900 to sounds.

The wireless communication interface 912 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 912 may typicallyinclude, for example, a BB processor 913 and an RF circuit 914. The BBprocessor 913 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 914 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives radio signals viathe antenna 916. The wireless communication interface 912 may also be aone chip module that has the BB processor 913 and the RF circuit 914integrated thereon. The wireless communication interface 912 may includethe multiple BB processors 934 and the multiple RF circuits 914, asillustrated in FIG. 33. Although FIG. 33 illustrates the example inwhich the wireless communication interface 912 includes the multiple BBprocessors 913 and the multiple RF circuits 914, the wirelesscommunication interface 912 may also include a single BB processor 913or a single RF circuit 914.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 912 may support a radio LANcommunication scheme. In that case, the wireless communication interface912 may include the BB processor 913 and the RF circuit 914 in the radioLAN communication scheme. Furthermore, in addition to a cellularcommunication scheme, the wireless communication interface 912 maysupport another type of wireless communication scheme such as ashort-distance wireless communication scheme and a near fieldcommunication scheme. In that case, the wireless communication interface912 may include the BB processor 913 and the RF circuit 914 for eachwireless communication scheme.

Each of the antenna switches 915 switches connection destinations of theantennas 916 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 912.

Each of the antennas 916 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 912 to transmit andreceive radio signals. The smartphone 900 may include the multipleantennas 916, as illustrated in FIG. 33. Although FIG. 33 illustratesthe example in which the smartphone 900 includes the multiple antennas916, the smartphone 900 may also include a single antenna 916.

Furthermore, the smartphone 900 may include the antenna 916 for eachwireless communication scheme. In that case, the antenna switches 915may be omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to blocksof the smartphone 900 illustrated in FIG. 33 via feeder lines, which arepartially shown as dashed lines in the figure. The auxiliary controller919 operates a minimum necessary function of the smartphone 900, forexample, in a sleep mode.

In the smartphone 900 illustrated in FIG. 33, the communication controlunit 241 described with reference to FIG. 11 may be implemented in thewireless communication interface 912 (for example, the BB processor913). Alternatively, at least a part of the communication control unit241 may be implemented in the processor 901 or the auxiliary controller919. As one example, the smartphone 900 is equipped with a moduleincluding a part (for example, the BB processor 913) or all of thewireless communication interface 912, the processor 901 and/or theauxiliary controller 919, and the communication control unit 241 may beimplemented in the module. In this case, the above-mentioned module maystore a program for causing the processor to function as thecommunication control unit 241 (in other words, a program for causingthe processor to execute the operation of the communication control unit241) and execute the program. As another example, a program for causingthe processor to function as the communication control unit 241 isinstalled in the smartphone 900, and the wireless communicationinterface 912 (for example, the BB processor 913), the processor 901,and/or the auxiliary controller 919 may execute the program. Asmentioned above, the smartphone 900, the base station device 820, or theabove-mentioned module may be provided as the device including thecommunication control unit 241, and the program for causing theprocessor to function as the communication control unit 241 may beprovided. Also, a readable storage medium storing the above-mentionedprogram may be provided. With respect to these points, the communicationcontrol unit 251 described with reference to FIG. 19 and thecommunication control unit 261 described with reference to FIG. 28 arealso similar to the communication control unit 241.

Also, in the smartphone 900 illustrated in FIG. 33, the wirelesscommunication unit 220 described, for example, with reference to FIG. 11may be implemented in the wireless communication interface 912 (forexample, the RF circuit 914). Also, the antenna unit 210 may beimplemented in the antenna 916.

SECOND APPLICATION EXAMPLE

FIG. 34 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technology ofthe present disclosure may be applied. The car navigation device 920includes a processor 921, a memory 922, a global positioning system(GPS) module 924, a sensor 925, a data interface 926, a content player927, a storage medium interface 928, an input device 929, a displaydevice 930, a speaker 931, a wireless communication interface 933, oneor more antenna switches 936, one or more antennas 937, and a battery938.

The processor 921 may be, for example, a CPU or a SoC, and controls anavigation function and another function of the car navigation device920. The memory 922 includes RAM and ROM, and stores a program that isexecuted by the processor 921, and data.

The GPS module 924 uses GPS signals received from a GPS satellite tomeasure a position (such as latitude, longitude, and altitude) of thecar navigation device 920. The sensor 925 may include a group of sensorssuch as a gyro sensor, a geomagnetic sensor, and an air pressure sensor.The data interface 926 is connected to, for example, an in-vehiclenetwork 941 via a terminal that is not shown, and acquires datagenerated by the vehicle, such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 928. The input device 929 includes, for example, a touchsensor configured to detect touch onto a screen of the display device930, a button, or a switch, and receives an operation or an informationinput from a user. The display device 930 includes a screen such as aLCD or an OLED display, and displays an image of the navigation functionor content that is reproduced. The speaker 931 outputs sounds of thenavigation function or the content that is reproduced.

The wireless communication interface 933 supports any cellularcommunication scheme such as LET and LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 933 may typicallyinclude, for example, a BB processor 934 and an RF circuit 935. The BBprocessor 934 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for wireless communication.Meanwhile, the RF circuit 935 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives radio signals viathe antenna 937. The wireless communication interface 933 may be a onechip module having the BB processor 934 and the RF circuit 935integrated thereon. The wireless communication interface 933 may includethe multiple BB processors 934 and the multiple RF circuits 935, asillustrated in FIG. 34. Although FIG. 34 illustrates the example inwhich the wireless communication interface 933 includes the multiple BBprocessors 934 and the multiple RF circuits 935, the wirelesscommunication interface 933 may also include a single BB processor 934or a single RF circuit 935.

Furthermore, in addition to a cellular communication scheme, thewireless communication interface 933 may support a radio LANcommunication scheme. In that case, the wireless communication interface933 may include the BB processor 934 and the RF circuit 935 in the radioLAN communication scheme. Furthermore, in addition to a cellularcommunication scheme, the wireless communication interface 933 maysupport another type of wireless communication scheme such as ashort-distance wireless communication scheme and a near fieldcommunication scheme. In that case, the wireless communication interface933 may include the BB processor 934 and the RF circuit 935 for eachwireless communication scheme.

Each of the antenna switches 936 switches connection destinations of theantennas 937 among multiple circuits (such as circuits for differentwireless communication schemes) included in the wireless communicationinterface 933.

Each of the antennas 937 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the wireless communication interface 933 to transmit andreceive radio signals. The car navigation device 920 may include themultiple antennas 937, as illustrated in FIG. 34. Although FIG. 34illustrates the example in which the car navigation device 920 includesthe multiple antennas 937, the car navigation device 920 may alsoinclude a single antenna 937.

Furthermore, the car navigation device 920 may include the antenna 937for each wireless communication scheme. In that case, the antennaswitches 936 may be omitted from the configuration of the car navigationdevice 920.

The battery 938 supplies power to blocks of the car navigation device920 illustrated in FIG. 34 via feeder lines that are partially shown asdashed lines in the figure. The battery 938 accumulates power suppliedform the vehicle.

In the car navigation device 920 illustrated in FIG. 34, thecommunication control unit 241 described with reference to FIG. 11 maybe implemented in the wireless communication interface 933 (for example,the BB processor 934). Alternatively, at least a part of thecommunication control unit 241 may be implemented in the processor 921.As one example, the car navigation device 920 is equipped with a moduleincluding a part (for example, the BB processor 934) or all of thewireless communication interface 933, and/or processor 921, and thecommunication control unit 241 may be implemented in the module. In thiscase, the above-mentioned module may store a program for causing theprocessor to function as the communication control unit 241 (in otherwords, a program for causing the processor to execute the operation ofthe communication control unit 241) and execute the program. As anotherexample, a program for causing the processor to function as thecommunication control unit 241 is installed in the car navigation device920, and the wireless communication interface 933 (for example, the BBprocessor 934), and/or the processor 921 may execute the program. Asmentioned above, the car navigation device 920, the base station device820, or the above-mentioned module may be provided as the deviceincluding the communication control unit 241, and the program forcausing the processor to function as the communication control unit 241may be provided. Also, a readable storage medium storing theabove-mentioned program may be provided. With respect to these points,the communication control unit 251 described with reference to FIG. 19and the communication control unit 261 described with reference to FIG.28 are also similar to the communication control unit 241.

Also, in the car navigation device 920 illustrated in FIG. 34, thewireless communication unit 220 described, for example, with referenceto FIG. 11 may be implemented in the wireless communication interface933 (for example, the RF circuit 935). Also, the antenna unit 210 may beimplemented in the antenna 937.

The technology of the present disclosure may also be realized as anin-vehicle system (or a vehicle) 940 including one or more blocks of thecar navigation device 920, the in-vehicle network 941, and a vehiclemodule 942. That is, the in-vehicle system (or the vehicle) 940 may beprovided as a device including the communication control unit 241 (orthe communication control unit 251 or 261). The vehicle module 942generates vehicle data such as vehicle speed, engine speed, and troubleinformation, and outputs the generated data to the in-vehicle network941.

7. CONCLUSION

The devices and the processes according to the embodiments of thepresent disclosure have been described with reference to FIGS. 1 to 34.

First Embodiment

According to the first embodiment, a frequency band shared betweencellular communication and other wireless communication (that is, ashared band) is occupied for the above-mentioned cellular communicationduring the first period, and released from the above-mentioned cellularcommunication during at least a second period corresponding to theabove-mentioned first period.

Thereby, for example, it is possible to secure an opportunity to use theabove-mentioned frequency band (that is, the shared band) in theabove-mentioned other wireless communication and continuously use thefrequency band for cellular communication for a certain amount of time.

Second Embodiment

According to the second embodiment, for example, before a period inwhich no signal is transmitted using a frequency band shared betweencellular communication and wireless LAN communication (that is, a sharedband) becomes a DIFS, a wireless communication device for performing thecellular communication is controlled so that the above-mentionedwireless communication device starts to transmit a signal using theabove-mentioned frequency band.

Thereby, for example, it is possible to more reliably secure theabove-mentioned frequency band for cellular communication.

Also, according to the second embodiment, for example, during a perioduntil a radio frame for another frequency band to be used in cellularcommunication starts, a wireless communication device for performing thecellular communication is controlled so that the wireless communicationdevice transmits a dummy signal using a frequency band shared betweenthe cellular communication and wireless LAN communication (that is, ashared band).

Thereby, for example, it is possible to more reliably secure theabove-mentioned frequency band for the cellular communication.

Third Embodiment

According to the third embodiment, a wireless communication device forperforming cellular communication is controlled so that theabove-mentioned wireless communication device transmits a signal using afrequency band (that is, shared band) shared between the cellularcommunication and other wireless communication.

Thereby, for example, a frequency band shared between the cellularcommunication and the other wireless communication (for example,wireless LAN communication) can be prevented from being used in theabove-mentioned other wireless communication while the frequency band isused for the cellular communication.

As described above, according to the embodiment of the presentdisclosure, for example, it is possible to more appropriately use afrequency band shared between wireless communication of a cellularsystem and other wireless communication in the above-mentioned cellularsystem.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples, of course. Aperson skilled in the art may find various alterations and modificationswithin the scope of the appended claims, and it should be understoodthat they will naturally come under the technical scope of the presentdisclosure.

Although an example in which the cellular system is a system conformingto LTE, LTE-Advanced, or a compliant communication scheme has beendescribed, the present disclosure is not limited to such an example. Forexample, the communication system may be a system conforming to anothercommunication standard.

Also, for example, an example in which other wireless communicationdifferent from wireless communication of the cellular system is wirelessLAN communication (that is, wireless communication conforming to thewireless LAN standard) has been described, but the present disclosure isnot limited to the relevant examples. For example, the above-mentionedother wireless communication may be wireless communication (wirelesscommunication conforming to another communication standard adoptingCSMA) other than the wireless LAN communication.

Also, the processing steps in each process in this specification are notstrictly limited to execution in a time series following the sequencedescribed in a flowchart or a sequence diagram. For example, theprocessing steps in each process may be executed in a sequence thatdiffers from a sequence described herein as a flowchart or a sequencediagram, and furthermore may be executed in parallel.

Also, it is possible to create a computer program for causing theprocessor (for example, a CPU, a DSP, etc.) provided in a device (forexample, the base station and/or the terminal device) of the presentdescription to function as the components (for example, thecommunication control unit) of the above-mentioned device (in otherwords, a computer program for causing the above-mentioned processor toexecute the operation of the components of the above-mentioned device).Also, a storage medium storing the computer program may be provided.Also, a device (for example, a completed product or a module (acomponent, a processing circuit, a chip, etc.) for a completed product)including a memory that stores the above-mentioned computer program andone or more processors capable of executing the above-mentioned computerprogram may be provided. Also, a method including the operation of thecomponents of the above-mentioned device (for example, the communicationcontrol unit) is included in the technology according to the presentdisclosure.

In addition, the advantageous effects described in this specificationare merely for the sake of explanation or illustration, and are notlimiting. In other words, instead of or in addition to the aboveadvantageous effects, technology according to the present disclosure mayexhibit other advantageous effects that are clear to persons skilled inthe art from the description of this specification.

Additionally, the present technology may also be configured as below.

-   (1)

A device including:

a control unit configured to occupy a frequency band shared betweenwireless communication of a cellular system and other wirelesscommunication for the wireless communication of the cellular systemduring a first period and release the frequency band from the wirelesscommunication of the cellular system during at least a second periodcorresponding to the first period.

-   (2)

The device according to (1), wherein the first period is a period of oneor more radio frames of the cellular system.

-   (3)

The device according to (1), wherein the first period is a continuousperiod.

-   (4)

The device according to (3), wherein the second period is a periodimmediately before or immediately after the first period.

-   (5)

The device according to (4), wherein the second period is a continuousperiod immediately after the first period.

-   (6)

The device according to (4), wherein the second period is a periodimmediately before the first period and a period immediately after thefirst period.

-   (7)

The device according to (4), wherein the second period is a continuousperiod immediately before the first period.

-   (8)

The device according to (3),

wherein the first period is a discontinuous period, and wherein thecontrol unit occupies the frequency band for the wireless communicationof the cellular system during the first period and releases thefrequency band from the wireless communication of the cellular systemduring at least the second period, within a third period.

-   (9)

The device according to any one of (1) to (8), wherein the second periodhas a length which is 90% to 110% of a length of the first period.

-   (10)

The device according to any one of (1) to (9), wherein the control unitoccupies the frequency band for the wireless communication of thecellular system during the first period by controlling a wirelesscommunication device for performing wireless communication of thecellular system so that the wireless communication device for performingthe wireless communication of the cellular system transmits a signalusing the frequency band during the first period.

-   (11)

The device according to (10), wherein the control unit controls thewireless communication device so that the wireless communication devicetransmits a signal using the frequency band at any time.

-   (12)

The device according to (11), wherein the control unit controls thewireless communication device so that transmission power of a signal tobe transmitted using the frequency band is greater than or equal topredetermined transmission power at any time.

-   (13)

The device according to (11) or (12), wherein the control unit controlsthe wireless communication device so that the wireless communicationdevice transmits a signal using the frequency band in each symbol.

-   (14)

The device according to (13), wherein the control unit controls thewireless communication device so that the wireless communication devicetransmits a dummy signal using the frequency band in at least a symbolin which neither a data signal nor a control signal of the cellularsystem is transmitted using the frequency band.

-   (15)

The device according to (14), wherein the control unit controls thewireless communication device so that the wireless communication devicetransmits the dummy signal in some radio resources among radio resourcesarranged in a frequency direction across the frequency band in at leastthe symbol.

-   (16)

The device according to (15), wherein the some radio resources are someresource blocks among resource blocks arranged in a frequency directionacross the frequency band.

-   (17)

The device according to (15), wherein the some radio resources are someresource elements included in each resource block arranged in afrequency direction across the frequency band.

-   (18)

The device according to any one of (11) to (17),

wherein the device is a base station for performing wirelesscommunication of the cellular system, a base station device for the basestation, or a module for the base station device, and

wherein the control unit instructs a terminal device for performingwireless communication of the cellular system to transmit a signal usingthe frequency band at any time for an uplink.

-   (19)

The device according to (18), wherein the control unit instructs each ofa plurality of terminal devices for performing wireless communication ofthe cellular system to transmit a signal using the frequency band at anytime for an uplink.

-   (20)

The device according to (18) or (19),

wherein the control unit instructs a plurality of terminal devices totransmit dummy signals in some radio resources among radio resourcesarranged in a frequency direction across the frequency band in at leasta symbol in which neither a data signal nor a control signal of thecellular system is transmitted using the frequency band for an uplink,and

wherein the some radio resources are common among a plurality ofterminal devices.

-   (21)

The device according to any one of (11) to (17),

wherein the device is a terminal device for performing wirelesscommunication of the cellular system or a module for the terminaldevice, and

wherein the control unit controls the terminal device so that theterminal device transmits a signal using the frequency band at any timefor an uplink.

-   (22)

The device according to any one of (1) to (9),

wherein the other wireless communication is wireless communicationconforming to a wireless local area network (LAN) standard, and

wherein the control unit occupies the frequency band for wirelesscommunication of the cellular system during the first period bycontrolling a wireless communication device for performing the wirelesscommunication of the cellular system so that the wireless communicationdevice transmits a frame including duration information for setting anetwork allocation vector (NAV) using the frequency band.

-   (23)

The device according to any one of (1) to (22), wherein the control unitreleases the frequency band from wireless communication of the cellularsystem during at least the second period by controlling a wirelesscommunication device for performing the wireless communication of thecellular system so that the wireless communication device does nottransmit a signal using the frequency band during at least the secondperiod.

-   (24)

The device according to any one of (10) to (23), wherein the wirelesscommunication device is at least one of a base station and a terminaldevice for performing wireless communication of the cellular system.

-   (25)

The device according to any one of (1) to (24), wherein the otherwireless communication is wireless communication conforming to awireless local area network (LAN) standard.

-   (26)

The device according to (25), wherein the control unit controls awireless communication device for performing wireless communication ofthe cellular system so that the wireless communication device starts totransmit a signal using the frequency band before a period in which nosignal is transmitted using the frequency band becomes a distributedcoordination function (DCF) inter-frame space (DIFS).

-   (27)

The device according to (26), wherein the control unit controls thewireless communication device so that the wireless communication devicestarts to transmit a signal using the frequency band after the period inwhich no signal is transmitted using the frequency band is longer than ashort inter-frame space (SIFS).

-   (28)

The device according to any one of (25) to (27), wherein the controlunit controls a wireless communication device for performing wirelesscommunication of the cellular system so that the wireless communicationdevice transmits a dummy signal using the frequency band during a perioduntil a radio frame for another frequency band to be used in thewireless communication of the cellular system starts.

-   (29)

The device according to any one of (24) to (26), wherein the controlunit controls a wireless communication device for performing wirelesscommunication of the cellular system so that the wireless communicationdevice transmits a frame including duration information for setting anNAV using the frequency band before a radio frame for another frequencyband to be used in the wireless communication of the cellular systemstarts.

-   (30)

The device according to any one of (26) to (29), wherein the wirelesscommunication device is at least one of a base station and a terminaldevice for performing wireless communication of the cellular system.

-   (31)

The device according to any one of (1) to (17) and (22) to (30), whereinthe device is a base station for performing wireless communication ofthe cellular system, a base station device for the base station, or amodule for the base station device.

-   (32)

The device according to any one of (1) to (17) and (22) to (30), whereinthe device is a terminal device for performing wireless communication ofthe cellular system or a module for the terminal device.

-   (33)

A method including:

occupying, by a processor, a frequency band shared between wirelesscommunication of a cellular system and other wireless communication forthe wireless communication of the cellular system during a first periodand releasing the frequency band from the wireless communication of thecellular system during at least a second period corresponding to thefirst period.

-   (34)

A program for causing a processor to execute:

occupying a frequency band shared between wireless communication of acellular system and other wireless communication for the wirelesscommunication of the cellular system during a first period and releasingthe frequency band from the wireless communication of the cellularsystem during at least a second period corresponding to the firstperiod.

-   (35)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute:

occupying a frequency band shared between wireless communication of acellular system and other wireless communication for the wirelesscommunication of the cellular system during a first period and releasingthe frequency band from the wireless communication of the cellularsystem during at least a second period corresponding to the firstperiod.

-   (36)

A device including: a control unit configured to control a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a signalusing a frequency band shared between the wireless communication of thecellular system and other wireless communication at any time.

-   (37)

An method including: controlling, by a processor, a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a signalusing a frequency band shared between the wireless communication of thecellular system and other wireless communication at any time.

-   (38)

A program for causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a signalusing a frequency band shared between the wireless communication of thecellular system and other wireless communication at any time.

-   (39)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a signalusing a frequency band shared between the wireless communication of thecellular system and other wireless communication at any time.

-   (40)

A device including: a control unit configured to control a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device starts to transmit asignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication before a periodin which no signal is transmitted using the frequency band becomes aDIFS.

-   (41)

A method including: controlling, by a processor, a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device starts to transmit asignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication before a periodin which no signal is transmitted using the frequency band becomes aDIFS.

-   (42)

A program for causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device starts to transmit asignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication before a periodin which no signal is transmitted using the frequency band becomes aDIFS.

-   (43)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device starts to transmit asignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication before a periodin which no signal is transmitted using the frequency band becomes aDIFS.

-   (44)

A device including: a control unit configured to control a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a dummysignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication during a perioduntil a radio frame for another frequency band to be used in thewireless communication of the cellular system starts.

-   (45)

A method including: controlling, by a processor, a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a dummysignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication during a perioduntil a radio frame for another frequency band to be used in thewireless communication of the cellular system starts.

-   (46)

A program for causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a dummysignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication during a perioduntil a radio frame for another frequency band to be used in thewireless communication of the cellular system starts.

-   (47)

A readable recording medium having a program recorded thereon, theprogram causing a processor to execute: controlling a wirelesscommunication device for performing wireless communication of a cellularsystem so that the wireless communication device transmits a dummysignal using a frequency band shared between the wireless communicationof the cellular system and other wireless communication during a perioduntil a radio frame for another frequency band to be used in thewireless communication of the cellular system starts.

-   (48)

The device according to any one of (36), (40), and (44), wherein thedevice is a base station for performing wireless communication of thecellular system, a base station device for the base station, or a modulefor the base station device.

-   (49)

The device according to any one of (36), (40), and (44), wherein thedevice is a terminal device for performing wireless communication of thecellular system or a module for the terminal device.

REFERENCE SIGNS LIST

-   1 cellular system-   10 cell-   30 access point-   40 communication area-   50 terminal device-   61 first period-   63 second period-   65 third period-   71 shared band-   100 base station-   151, 161, 171 communication control unit-   200 terminal device-   241, 251, 261, 271 communication control unit

1. A communication control device comprising: processing circuitryconfigured to communicate with a terminal device via a plurality ofcomponent carriers according to carrier aggregation, the plurality ofcomponent carriers including a primary component carrier and a secondarycomponent carriers, the secondary component carrier being controllableto be activated and deactivated; and control setting a first period anda second period, the secondary component carrier being configured byoccupying an unlicensed frequency band shared between wirelesscommunication of a cellular system and wireless communication of awireless local area network during the first period, the unlicensedfrequency band being released from the secondary component carrierduring the second period, wherein the first period has a variable lengthdepending on a length of the second period such that the first periodmaintains a length that is a predetermined percentage of the length ofthe second period.
 2. The communication control device according toclaim 1, wherein the first period is a period of one or more radioframes of the cellular system.
 3. The communication control deviceaccording to claim 1, wherein the first period is a continuous period.4. The communication control device according to claim 3, wherein thesecond period is a period immediately before or immediately after thefirst period.
 5. The communication control device according to claim 4,wherein the second period is a continuous period immediately after thefirst period.
 6. The communication control device according to claim 4,wherein the second period is a period immediately before the firstperiod and a period immediately after the first period.
 7. Thecommunication control device according to claim 4, wherein the secondperiod is a continuous period immediately before the first period. 8.The communication control device according to claim 3, wherein the firstperiod is a discontinuous period, and wherein the processing circuitryoccupies the frequency band for the wireless communication of thecellular system during the first period and releases the frequency bandfrom the wireless communication of the cellular system during at leastthe second period, within a third period.
 9. The communication controldevice according to claim 1, wherein the second period has a lengthwhich is 90% to 110% of a length of the first period.
 10. Thecommunication control device according to claim 1, wherein theprocessing circuitry occupies the frequency band for the wirelesscommunication of the cellular system during the first period bycontrolling a wireless communication device for performing wirelesscommunication of the cellular system so that the wireless communicationdevice for performing the wireless communication of the cellular systemtransmits a signal using the frequency band during the first period. 11.The communication control device according to claim 10, wherein theprocessing circuitry controls the wireless communication device so thatthe wireless communication device transmits a signal using the frequencyband at any time.
 12. The communication control device according toclaim 11, wherein the processing circuitry controls the wirelesscommunication device so that transmission power of a signal to betransmitted using the frequency band is greater than or equal topredetermined transmission power at any time.
 13. The device accordingto claim 11, wherein the processing circuitry controls the wirelesscommunication device so that the wireless communication device transmitsa signal using the frequency band in each symbol.
 14. The communicationcontrol device according to claim 13, wherein the processing circuitrycontrols the wireless communication device so that the wirelesscommunication device transmits a dummy signal using the frequency bandin at least a symbol in which neither a data signal nor a control signalof the cellular system is transmitted using the frequency band.
 15. Thecommunication control device according to claim 14, wherein theprocessing circuitry controls the wireless communication device so thatthe wireless communication device transmits the dummy signal in someradio resources among radio resources arranged in a frequency directionacross the frequency band in at least the symbol.
 16. The communicationcontrol device according to claim 15, wherein the some radio resourcesare some resource blocks among resource blocks arranged in a frequencydirection across the frequency band.
 17. The communication controldevice according to claim 15, wherein the some radio resources are someresource elements included in each resource block arranged in afrequency direction across the frequency band.
 18. The communicationcontrol device according to claim 11, wherein the communication controldevice is a base station for performing wireless communication of thecellular system, a base station device for the base station, or a modulefor the base station device, and wherein the processing circuitryinstructs a terminal device for performing wireless communication of thecellular system to transmit a signal using the frequency band at anytime for an uplink.
 19. The communication control device according toclaim 18, wherein the processing circuitry instructs each of a pluralityof terminal devices for performing wireless communication of thecellular system to transmit a signal using the frequency band at anytime for an uplink.
 20. The communication control device according toclaim 18, wherein the processing circuitry instructs a plurality ofterminal devices to transmit dummy signals in some radio resources amongradio resources arranged in a frequency direction across the frequencyband in at least a symbol in which neither a data signal nor a controlsignal of the cellular system is transmitted using the frequency bandfor an uplink, and wherein the some radio resources are common among aplurality of terminal devices.
 21. A terminal device comprising:processing circuitry configured to: communicate with a base station viaa plurality of component carriers according to carrier aggregation, theplurality of component carriers including a primary component carrierand a secondary component carriers, the secondary component carrierbeing controllable to be activated and deactivated; and recognize afirst period and a second period, the secondary component carrier beingconfigured by occupying an unlicensed frequency band shared betweenwireless communication of a cellular system and wireless communicationof a wireless local area network during the first period, the unlicensedfrequency band being released from the secondary component carrierduring the second period, wherein the first period has a variable lengthdepending on a length of the second period such that the first periodmaintains a length that is a predetermined percentage of the length ofthe second period.
 22. A method, implemented by a communication controldevice, comprising: communicating with a terminal device via a pluralityof component carriers according to carrier aggregation, the plurality ofcomponent carriers including a primary component carrier and a secondarycomponent carriers, the secondary component carrier being controllableto be activated and deactivated; and controlling setting a first periodand a second period, the secondary component carrier being configured byoccupying an unlicensed frequency band shared between wirelesscommunication of a cellular system and wireless communication of awireless local area network during the first period, the unlicensedfrequency band being released from the secondary component carrierduring the second period, wherein the first period has a variable lengthdepending on a length of the second period such that the first periodmaintains a length that is a predetermined percentage of the length ofthe second period.